Question

3x-4y=10 2x-3y=7 use the elimination system

Answer 1

3x-4y=10
2x-3y=7
equiv a
9x-12y=30
8x-12y=28
9x-12y-(8x-12y)=x=2

Answer 2

\(\large \begin{array}{llll}
3x-4y=10&{\color{red}{ \times -3}}\implies &-9x+12y=-30\\
2x-3y=7&{\color{red}{ \times 4}}\implies &\quad 8x-12y=28\\
\hline\\
&&-x\qquad \qquad =-18
\end{array}\)

Answer 3

3x - 4y = 10 --->(3)
2x - 3y = 7 --->(-4)
----------------
9x - 12y = 30 (result of multiplying by 3)
-8x + 12y = - 28 (result of multiplying by -4)
----------------add
x = 2
now sub 2 in for x in either equation to find y
3x - 4y = 10
3(2) - 4y = 10
6 - 4y = 10
-4y = 10 - 6
-4y = 4
y = -1

check..
2x - 3y = 7
2(2) - 3(-1) = 7
4 + 3 = 7
7 = 7 (correct)

solution (2,-1)

any questions ?

Answer 4

\(\large \begin{array}{llll}
3x-4y=10&{\color{red}{ \times -3}}\implies &-9x+12y=-30\\
2x-3y=7&{\color{red}{ \times 4}}\implies &\quad 8x-12y=28\\
\hline\\
&&-x\qquad \qquad =-2
\end{array}\) rather... anyhow

so you'd substitute that value on either equation to find "y"
as shown already