How do you solve this 7x-4y-9 and 3x 2y-15 find x and y?

Answer 1

A1:

7x-4y=9 , 3x+2y=15 and 7x-4y=9, 6x+4y=30 so 13x=39 x=3 now plug it in for y

9+2y=15 so y=3 A2:

The right expression is missing a + or - between the 3x and 2y. For the purpose of this demo, let's assume it is 3x+2y-15.

It can be solved by multiplying the right expression by 2, then add the expressions. That will eliminate y. Then solve for x. When x is known, plug its value into either of the expressions and solve for y. To start: 2(3x+2y-15)=6x+4y-30

adding the two

(7x-4y-9)+(6x+4y-30)=13x+0y-39=13x-39

solve for x