Question

If 7x−6y=2 and −2x−y=3 are true equations, what would be the value of 5x−7y?

Answer 1

-55

Explanation:

7x-6y=2

-2x-y=3

by substitution method

y=3+2x

7x-6(3+2x)=2

7x-18-12x=2

-5x=20

x=-4

-2(-4)-y=3

8-y=3

-y=3-8

y=5

therefore the value of x=4 and that of y=5

5x-7y=5(-4)-7(5)

=-20-35

=-55