Question

Solve for d.

Answer 1

$5d+2(2-d)=3(1+d)+1 \\ 5d+4-2d=3+3d+1 \\ 3d+4=3d+4 \\ 0=0 \\ \boxed{C.\ Infinitely\ many\ solutions}$

Answer 2

5d + 2(2 - d) = 3(1 + d) + 1
5d + 2(2) - 2(d) = 3(1) + 3(d) + 1
5d + 4 - 2d = 3 + 3d + 1
5d - 2d + 4 = 3d + 3 + 1
3d + 4 = 3d + 4
-3d       -3d       
       4 = 4
       d = 0