ANSWER
A. (4,12)
EXPLANATION
The equations are:
[tex]10x +2y = 64...(1)[/tex]
and
[tex]3x - 4y = -36...(2)[/tex]
To eliminate a variable we make the coefficients of that variable the same in both equations.
It is easier to eliminate x.
We multiply the first equation by 2 to get:
[tex]20x + 4y = 128...(3)[/tex]
We add equations (2) and (3).
[tex]3x + 20x + 4y - 4y = - 36 + 128[/tex]
[tex]23x = 92[/tex]
Divide both sides by 23
[tex] \frac{23x}{23} = \frac{92}{23} [/tex]
[tex]x = 4[/tex]
Put x=4 into equation (1).
[tex]10(4)+2y = 64[/tex]
[tex]40+2y = 64[/tex]
[tex]2y = 64 - 40[/tex]
[tex]2y = 24[/tex]
[tex] \frac{2y}{2} = \frac{24}{2} [/tex]
[tex]y = 12[/tex]
The solution is (4,12)
