Question

If 2w + 4t = 14 and 4w + 5t = 25, what is the value

of 2w + 3t ?
A) 6
B) 10
C) 13
D) 17

Answer 1

C

Explanation:

find the value of w and t by solving the equations simultaneously.

2w + 4t = 14 → (1)

4w + 5t = 25 → (2)

multiplying (1) by - 2 and adding to (2) will eliminate w

- 4w - 8t = - 28 → (3)

add (2) + (3) term by term to eliminate w

0 - 3t = - 3

- 3t = - 3 ( divide both sides by - 3 )

t = 1

substitute t = 1 into either of the 2 equations and solve for w

substituting into (1)

2w + 4(1) = 14

2w + 4 = 14 ( subtract 4 from both sides )

2w = 10 ( divide both sides by 2 )

w = 5

Then

2w + 3t = 2(5) + 3(1) = 10 + 3 = 13