1.
Find the value of the expression x + 2 for x = -2
2.
What should be subtracted from x² + y²  2xy to get x² + y²? 
3.
What should be added to x² + y² to get x² + y² + 2 xy? 
4.
Subtract y² from  5y²
5.
Subtract xy from xy
6.
Simplify : p + (p q) + q + (q p)
7.
Simplify : z² + 11z²  5z  11z² + 5z 
8.
Add 4x²y, -3x²y, -7xy², 7xy² 
9.
Add 2 mn, -4 mn, 8 mn, -6 mn
10.
Add a + b 1, b a + 1, 1 26