The answer is 20. in simply form but the one that is not simply is 20/1/ There the same.
The pages would be 166 and 167
Take into account that commutative property is present for addition and multiplication operations, then, you have:
3+5=5+3 TRUE
3·5 = 5·3 TRUE
The inverse addition of a number consists in adding the same numbers but with opposite signs, then, you have:
2 + (-2) = 0 TRUE
