Question

Suni needs to solve the system of equations using

addition. What variable should she solve for first? Find the solution.
- 5x + 3y = 15
2x – 3y = - 15
What variable should Suni solve for first?

Answer 1

solve for x first

Explanation:

Given the 2 equations

- 5x + 3y = 15 → (1)

2x - 3y = - 15 → (2)

Add the 2 equations term by term to eliminate y

- 3x + 0 = 0

- 3x = 0

x = 0

Substitute x = 0 into either of the 2 equations and solve for y

Substituting into (2)

2(0) - 3y = - 15

- 3y = - 15 ( divide both sides by - 3 )

y = 5

solution is (0, 5 )