156k views
5 votes
Solve the system by substitution 5x+y=-10. 4x-7y=-8

User Nianliang
by
6.9k points

1 Answer

6 votes

Answer:

x = -2 and y = 0

Explanation:

5x + y = -10

4x - 7y = -8

Rearrange the first equation to equal y.

5x + y = -10

y = -10 - 5x

Replace y in the second equation with the first equation.

4x - 7y = -8

4x - 7(-10 - 5x) = -8

4x - (-70 -35x) = -8

4x + 70 + 35x = -8

Rearrange the equation to find x.

4x + 35x = -8 - 70

39x = -78

x = -2

Now that you know x, use the rearranged first equation to find y.

y = -10 - 5x

y = -10 - 5(-2)

y = -10 + 10

y = 0

User Ramasamy Kanna
by
7.1k points