If $2 x-1=5$ and $3 y+2=17$, then the value of $2 x+3 y$ is
(A) 8
(B) 19
(C) 21
(D) 23
(E) 25
If $2 x-1=5$ and $3 y+2=17$, then the value of $2 x+3 y$ is
(A) 8
(B) 19
(C) 21
(D) 23
(E) 25

Solution

$$
\begin{aligned}
& 2 x-1=5 \quad, \quad 3 y+2=17 \\
& 2 x=6 \quad 3 y=15
\end{aligned}
$$

Thus, $2 x+3 y=6+15=21$.

ANSWER: (C)

Note: It is not necessary to solve the equations to find actual values for $x$ and $y$ although this would of course lead to the correct answer. It is, however, a little more efficient to solve for $2 x$ and $3 y$.