Question

Question 7 (Essay Worth 2 points)

(05.03 MC)
A system of equations is given.
Equation 1: 5x - 2y = 10
Equation 2: 4x - 3y = 15
Explain how to eliminate x in the system of equations.

Answer 1

see explanation

Explanation:

given

5x - 2y = 10 → (1)

4x - 3y = 15 → (2)

multiplying (1) by 4 and (2) by - 5 ( coefficients of the x- terms with a negative placed on the 5 ) and adding the result will eliminate x

20x - 8y = 40 → (3)

- 20x + 15y = - 75 → (4)

add (3) and (4) term by term to eliminate x

(20x - 20x) + (- 8y + 15y) = 40 - 75

0 + 7y = - 35 ← x has been eliminated

7y = - 35

y = - 5