Question

What is the solution to this system of equations 3x + 2y =45 4x- y = 5

Answer 1

x = 5 and y = 15

Explanation:

3x + 2y = 45 (call this equation '1')

4x - y = 5 (call this equation '2')

multiply '2' by two

8x - 2y = 10 (call this equation '3')

add '1' and '3'

(3+8)x + (-2 + 2)y = (45 + 10)

11x = 55

x = 5.

now substitute this value into '1'

3x + 2y = 45

3(5) + 2y = 45

15 + 2y = 45

2y = 45 - 15 = 30

y = 15

now substitute x = 5 and y =15 into '2' to check if they're correct

4x - y = 5

4(5) - 15 = 5

20 - 15 = 5.

So, x = 5 and y = 15