Question

If 2( x + y ) = , what is the value of 3x + 3y?

A. 5
B. 7
C. 8
D. 9
E. 12

(Please explain)

Answer 1

$2( x + y ) = 6|\div 2\\ x+y=3|\cdot3\\ 3x+3y=9\implies \text{D}$

Answer 2

$\bf 2(x+y)=6\implies (x+y)=\cfrac{6}{2}\implies \boxed{(x+y)=3} \\\\\\ 3x+3y\implies 2x+x+2y+y\implies (x+y)+(2x+2y) \\\\\\ \stackrel{3}{(x+y)}+\stackrel{6}{2(x+y)}\implies 3+6\implies 9$