Question

If the expression 3x + 2 is equal to 15 for some value of x, then which of the following is the value of 9x+5 for the same value of x?

(1) 40
(2) 46
(3) 44
(4) 50

Answer 1

First isolate the variable x in 3x+2=15. Subtract 2 from both sides so that you get 3x=13. Divide 3 by both sides and you get x=4 1/3. Since you keep the same value as x then you substitute in 4 1/3 in 9x+5 so that it looks like 9(4 1/3)+5 which would then equal to 44. Choice 3 would be correct.

Answer 2

44

Explanation:

3x + 2 = 15

solve for x

x = 13/3

take this value and plug into the second expression and solve.

(9 x 13/3) + 5 = 44