If, for example, you had x on one side and x on the other, then subtracting x from both sides "disappears" x. If no other power of x shows up on either side, then your equation either has no solution or is always true.
1. 7 + 15 + 12 + 5 + 5 + 10 = 54
54 x 2.5 = $135
The correct answer is $135
2. A^2 + 9^2 = 22^2
A^2 + 81 = 484
A^2 = 403
Square root of a and 403
A= 20.7
20.7 + 22 + 9 = 51.7
The correct answer is (3)
3.) 2 × 0.5 = 1
4.) -2 × -0.5 = 1
3ab - 3a - 8 + 4ab + 8
7ab -3a