-6
If: d+7 = 5 Then: d = -2 by subtracting 7 from both sides
c = 6 and d = 7
4
Commutativity.
d=17
the answer is a
-6
If: d+7 = 5 Then: d = -2 by subtracting 7 from both sides
c = 6 and d = 7
4
Commutativity.
Doc, Happy, Grumpy, Sleepy, Bashful, Sneezy and Dopey equal[s] the 7 dwarves.
That's the equation.
15d + 7 = 7d + 15 is an equation in one variable, d.
2d + 7 = 9 2d = 2 d = 1
5x+y=-7 3x+y=15 8=D