What is 7x - y = - 10 - 7x + 5y = - 6 (elimination method) step by step

Question

Mathematics

Koty

3 September, 12:43

What is 7x - y = - 10 - 7x + 5y = - 6 (elimination method) step by step

+4

Answers (1)

Know the Answer?

London Robinson · Answer 1

7x - y = - 10 ... (1)

-7x + 5y = - 6 ... (2)

Add (1) and (2)

7x-y + (-7x) + 5y = - 10-6

=>

5y-y = - 16

=>

4y=-16

=>

y=-16/4=-4

Substitute y in (1)

7x - (-4) = - 10

7x=-10-4=-14

=>

x=-14/7=-2

Answer: the solution is x=-2, y=-4, or (-2,-4)

Check:

7 (-2) - (-4) = - 14+4=-10 ok

-7 (-2) + 5 (-4) = 14-20=-6 ok