Question

If 2x + y = 23 and 4x – y = 19; find the value of x – 3y and 5y – 2x

Answer 1

Answer:

- 20 and 31

Step-by-step explanation:

Solve the given equations simultaneously to find x and y

2x + y = 23 → (1)

4x - y = 19 → (2)

Adding the 2 equations term by term will eliminate y

6x + 0 = 42

6x = 42 ( divide both sides by 6 )

x = 7

Substitute x = 7 into either of the 2 equations and solve for y

Substituting into (1)

2(7) + y = 23

14 + y = 23 ( subtract 14 from both sides )

y = 9

Then

x - 3y = 7 - 3(9) = 7 - 27 = - 20

5y - 2x = 5(9) - 2(7) = 45 - 14 = 31