Algebra 2 Help

[Bacon Boy]

I'm no good at these things. Failed this portion of a pre-test I took at the beginning of the year. I've worked out every possible way i can think of, but I cannot get the answer.

Problem: Solve each equation.

(4x ⁄ 5) + (3x-2 ⁄ 10) = (x + 6 ⁄ 4)

I can get to 16x ⁄ 20 + 6x - 4 ⁄ 20 = 5x + 30 ⁄ 20
But the answer always comes out to x = 27 ⁄ 26 which does not work when you plug it back into the equation...

FYI: ⁄ = Fractions
I suck at math, btw.

 

[Sporge27]

I get x=17/28

remember to multiply some terms by one occasionally, only say make it multiply that 6x by 20/20 allowing you to combine it with the term next door.

I could be wrong, did it kinda quickly.

 

[Bacon Boy]

I get x=17/28

remember to multiply some terms by one occasionally, only say make it multiply that 6x by 20/20 allowing you to combine it with the term next door.

I could be wrong, did it kinda quickly.

I don't understand. I got 6x by finding the LCD. It's not a part of the original equation.

 

[Sporge27]

4x ⁄ 5 + 3x - 2 ⁄ 10 = x + 6 ⁄ 4
first get all x values to one side, and all not to the other.

->4x/5 + 2x = 6/4 + 2/10

then adjust things to be usable in the next couple steps
->4x/5+10/10(2/x) = (6/2(5/5) + 2/5(2/2))1/2

->4x/5 +10x/5= (30/10+4/10)1/2

-> 14x/5 = 34/20

->14x = 34/4 = 17/2

->x = 17/28

 

[Bacon Boy]

4x ⁄ 5 + 3x - 2 ⁄ 10 = x + 6 ⁄ 4
first get all x values to one side, and all not to the other.

->4x/5 + 2x = 6/4 + 2/10

then adjust things to be usable in the next couple steps
->4x/5+10/10(2/x) = (6/2(5/5) + 2/5(2/2))1/2

->4x/5 +10x/5= (30/10+4/10)1/2

-> 14x/5 = 34/20

->14x = 34/4 = 17/2

->x = 17/28

Plugging it back into the original equation those, it doesn't work.

Dammit. I meant ⁄ = Fractions.

 

[Sporge27]

wait... rewrite the problem with () around the fractions.... that might help

 

[Bacon Boy]

(4x ⁄ 5) + (3x-2 ⁄ 10) = (x + 6 ⁄ 4)

Fix'd.

 

[«Jack»]

x = 17

Multiply everything by 5 to get 4x + (15x-10/10) = 5x + (30/4)
Multiply everything by 10 to get 40x + 15x -10 = 50x + (300/4)
Subtract 10 and simplify 300/4 to get 40x +15x = 50x + 65
Subtract 50x and combine like terms to get 5x = 65
Divide by 5 to get 17

 

[Sporge27]

ah that looks better then, I got x =2.

(4x ⁄ 5) + ((3x-2 )⁄ 10) = ((x + 6) ⁄ 4)

multiply both sides by 5

4x+ ((3x-2)/2)=((5x+30)/4)

multiply both sides by 4

16x + 6x - 4 = 5x + 30

17x = 34

x=2

 

[«Jack»]

Disregard mine, Sporge has the correct groupings. I read (x+6)/4) as x + (6/4)

 

[Bacon Boy]

ah that looks better then, I got x =2.

(4x ⁄ 5) + ((3x-2 )⁄ 10) = ((x + 6) ⁄ 4)

multiply both sides by 5

4x+ ((3x-2)/2)=((5x+30)/4)

multiply both sides by 4

16x + 6x - 4 = 5x + 30

17x = 34

x=2

Why didn't you multiply the bolded four by 5, though?

 

[«Jack»]

ah that looks better then, I got x =2.

(4x ⁄ 5) + ((3x-2 )⁄ 10) = ((x + 6) ⁄ 4)

multiply both sides by 5

4x+ ((3x-2)/2)=((5x+30)/4)

multiply both sides by 4

16x + 6x - 4 = 5x + 30

17x = 34

x=2

Why didn't you multiply the bolded four by 5, though?

It's on the bottom of the fraction, so it isn't multiplied. Think of the multiplying by five as (5/1). The 4 is paired with the one when multiplied, so it doesn't change.

 

[Bacon Boy]

ah that looks better then, I got x =2.

(4x ⁄ 5) + ((3x-2 )⁄ 10) = ((x + 6) ⁄ 4)

multiply both sides by 5

4x+ ((3x-2)/2)=((5x+30)/4)

multiply both sides by 4

16x + 6x - 4 = 5x + 30

17x = 34

x=2

Why didn't you multiply the bolded four by 5, though?

It's on the bottom of the fraction, so it isn't multiplied. Think of the multiplying by five as (5/1). The 4 is paired with the one when multiplied, so it doesn't change.

So you multiply the left half by 1/5 but the right half by 5/1? That doesn't make any sense.

 

[Sporge27]

ah that looks better then, I got x =2.

(4x ⁄ 5) + ((3x-2 )⁄ 10) = ((x + 6) ⁄ 4)

multiply both sides by 5

4x+ ((3x-2)/2)=((5x+30)/4)

multiply both sides by 4

16x + 6x - 4 = 5x + 30

17x = 34

x=2

Why didn't you multiply the bolded four by 5, though?

that is on the bottom of the / , both terms on top are multiplied,

example

(*=multiply)

(1/2 ) * 5 = 5/2 not (1/2)*5 = 5/10

make sense?

 

[Bacon Boy]

ah that looks better then, I got x =2.

(4x ⁄ 5) + ((3x-2 )⁄ 10) = ((x + 6) ⁄ 4)

multiply both sides by 5

4x+ ((3x-2)/2)=((5x+30)/4)

multiply both sides by 4

16x + 6x - 4 = 5x + 30

17x = 34

x=2

Why didn't you multiply the bolded four by 5, though?

that is on the bottom of the / , both terms on top are multiplied,

example

(*=multiply)

(1/2 ) * 5 = 5/2 not (1/2)*5 = 5/10

make sense?

Like I said in a post before, why did you multiply them differently. It looks like you multiplied the left half by 1/5 and the right by 5/1.

 

[«Jack»]

ah that looks better then, I got x =2.

(4x ⁄ 5) + ((3x-2 )⁄ 10) = ((x + 6) ⁄ 4)

multiply both sides by 5

4x+ ((3x-2)/2)=((5x+30)/4)

multiply both sides by 4

16x + 6x - 4 = 5x + 30

17x = 34

x=2

Why didn't you multiply the bolded four by 5, though?

It's on the bottom of the fraction, so it isn't multiplied. Think of the multiplying by five as (5/1). The 4 is paired with the one when multiplied, so it doesn't change.

So you multiply the left half by 1/5 but the right half by 5/1? That doesn't make any sense.

The left half is being multiplied by 5. Sporge just simplified the second part to avoid unwieldy numbers.
(15x-10)/10 is the same as (3x-2)/2

 

[Sporge27]

(4x ⁄ 5) + ((3x-2 ) / 10) = ((x + 6) ⁄ 4)

5*(4x ⁄ 5) + 5*((3x-2 )⁄ 10) = 5*((x + 6) ⁄ 4)

cancels____cancels_________multiplied into top term
4x________+ ((3x-2)/2) ____= ______ ((5x+30)/4)

 

[Bacon Boy]

Quoting limited to 4 levels deep4

It's on the bottom of the fraction, so it isn't multiplied. Think of the multiplying by five as (5/1). The 4 is paired with the one when multiplied, so it doesn't change.

So you multiply the left half by 1/5 but the right half by 5/1? That doesn't make any sense.

The left half is being multiplied by 5. Sporge just simplified the second part to avoid unwieldy numbers.
(15x-10)/10 is the same as (3x-2)/2

I see. Otherwise it would be ((15x-10)⁄50).

I understood everything else, save that. Thanks guys.

 

[fantanoice]

I'm no good at these things. Failed this portion of a pre-test I took at the beginning of the year. I've worked out every possible way i can think of, but I cannot get the answer.

Problem: Solve each equation.

(4x ⁄ 5) + (3x-2 ⁄ 10) = (x + 6 ⁄ 4)

I can get to 16x ⁄ 20 + 6x - 4 ⁄ 20 = 5x + 30 ⁄ 20
But the answer always comes out to x = 27 ⁄ 26 which does not work when you plug it back into the equation...

FYI: ⁄ = Fractions
I suck at math, btw.

(4x ⁄ 5) + (3x-2 ⁄ 10) = (x + 6 ⁄ 4)

I'm guessing you actually meant to write:

4x/5 + (3x-2)/10 = x + 6/4

The key is to get rid of the denominators. Multiply all by 10 (you can't use 5 because it doesn't rationalise properly) to get rid of the fractions.

==> 10(4x/5 + (3x-2)/10) = 10(x + 6/4)
==> 40x/5 + 3x - 2 = 10x + 60/4

Then just simplify:

==> 8x + 3x - 2 = 10x + 15
==> 11x - 2 = 10x + 15
==> x - 2 = 15
==> x = 17


Now use that answer to see if it works:

4(17)/5 + (3(17)-2)/10 = 17 + 6/4
==> 68/5 + (51-2/10) = 17 + 6/4
==> 68/5 + 49/10 = 17 + 6/4
==> 272/20 + 98/20 = 340/20 + 30/20
==> 370/20 = 370/20

So yes, it works. Whoop whoop.


Hope that helps, bru.

 

[Bacon Boy]

x=2 was the right answer. x=17 didn't work when you plugged it into the calculator or when I plugged it in. I originally had the right set-up, I was just doingitwrong.