x = 11, which equation is true?

Question

A 3(14 – x) = 123(14 – x ) = 12
B 2x + 5 = 242 x + 5 = 24
C 2(20 – x) = 182(20 – x ) = 18
D 4(2x – 11) = 554(2x – 11) = 55

Answer 1

To determine which equation is true, we can substitute x = 11 into each equation and see if both sides are equal.

A) 3(14 - x) = 12
3(14 - 11) = 3(3) = 9

The left side of the equation does not equal the right side, so this equation is not true.

B) 2x + 5 = 24
2(11) + 5 = 22 + 5 = 27

The left side of the equation does not equal the right side, so this equation is not true.

C) 2(20 - x) = 18
2(20 - 11) = 2(9) = 18

The left side of the equation equals the right side, so this equation is true.

D) 4(2x - 11) = 55
4(2(11) - 11) = 4(22 - 11) = 4(11) = 44

The left side of the equation does not equal the right side, so this equation is not true.

Therefore, the equation that is true when x = 11 is C) 2(20 - x) = 18.