Question

which equation is true for the value of x = 15?A. 2(x + 3) = 40B. 2(x - 5) = 30C. 2(x + 5) = 40please try to explain it to the best of your ability, thanks!

Answer 1

Substitute x=15 in the first expression 2(x+3)=40.

$\begin{gathered} 2\times(15+3)=40 \\ 2\times18=40 \\ 36=40 \end{gathered}$

36 is not equals to 40. Thus, the above expression is wrong.

Substitute x=15 in the second expression. 2(x-5)=30

$\begin{gathered} 2\times(15-5)=30 \\ 2\times10=30 \\ 20=30 \end{gathered}$

The above expression is also not true since 20 is not equals to 30.

Substitute x=15 in the third expression. 2(x+5)=40

$\begin{gathered} 2(15+5)=40 \\ 2\times20=40 \\ 40=40 \end{gathered}$

The above expression is true. Thus, the value x=15 is true for the expression 2(x+5)=40.