Question

-14x=-7-7Y

-10X=-15-7Y

Answer 1

lets rearrange..
-14x = -7 - 7y
-14x + 7 = -7y
-14x/-7 + 7/-7 = -7y/-7
2x - 1 = y

so now we sub 2x - 1 in for y in the other equation to find x
-10x = -15 - 7y
-10x = -15 - 7(2x - 1) --- distribute through the parenthesis
-10x = -15 - 14x + 7 --- add 14x to both sides
-10x + 14x = -15 + 7 --- combine like terms
4x = - 8
x = -8/4
x = -2

now sub -2 in for x in either of the original equations to find y
-14x = -7 - 7y
-14(-2) = -7 - 7y
28 = -7 - 7y
28 + 7 = -7y
35 = -7y
35/-7 = y
-5 = y

check..
-10x = -15 - 7y
-10(-2) = -15 - 7(-5)
20 = -15 + 35
20 = 20 (correct)

so x = -2 and y = -5