Question

(algebra 1) finding an x-value using x+y = a
(question in the replies)

Answer 1

So this method only works when you have a value on either equation that can multiply to equal the other, since you have a 15 x and a 30x, you can multiply, multiply the ENTIRE top equation by 2

Answer 2

Resulting in 30x-24y=26

Answer 3

Now subtract the equations.

Answer 4

Which results in -33y =22

Answer 5

So then \[{y=-}\frac{2}{3}\]

Answer 6

it's easy if you have notes too if you ever need help with algerbra 1 i can help

Answer 7

Now plug the y value into one of the two original equations, preferably the simpler one

Answer 8

which would give you 64/99

Answer 9

but simplify it first

Answer 10

i think

Answer 11

So then \[{15x-12*\frac{-2}{3}}=13}

Answer 12

15x minus 12(-2/3) =13

Answer 13

And -12 times -2/3 =8

Answer 14

Then 15x+3=8

Answer 15

So subtracting 3 from both sides is 15x = 5, dividing by 5 gives you \[{x=3}\]

Answer 16

Hope this helped! \[{x=3}\]

Answer 17

If you need a better explanation (I know I was all over the place) DM me and I'll get you a simplified one.