122k views
5 votes
2x + 5y = 7
2x - 3y = 15

User Ichimok
by
5.1k points

1 Answer

0 votes

Answer:

1. 2x + 5y = 7

2. 3x + 6y = 3

Multiply Equation 1. by -3 and Equation 2. by 2:

1'. -6x - 15y = -21

2'. 6x + 12y = 6

Add Equations 1' and 2' to eliminate x

y(-15 + 12) = (-21 + 6)

-3y = -15

y = 5

Substitute this value of y into either Equation 1 or 2 and solve for x:

1. 2x + 5y = 7 ⇒ 2x + 5(5) = 7

2x = (7 - 25) = -18

x = -9

Check answer:

Does 3(-9) + 6(5) = 3?

Does -27 + 30 = 3?

YES!!

Explanation:

User Biobirdman
by
4.3k points