First, let's declare our variables
B = x+2
A = 3(x+2)
Now, let's create our expression.
A + B = 128
Plug in the values for A and B
x+2 + 3(x+2) = 128
We need to solve for x. Start off by simplifying the left side.
x+2 + 3x + 6 = 128
Combine like terms.
4x + 8 = 128
Subtract 8 from both sides.
4x = 120
Divide both sides by 4
x = 30
B = x+2 = 30 + 2 = 32 degrees
A = 3(x+2) = 3(30+2) = 3(32) = 96 degrees