18. equivalent
16x5 does equal 10x8
19. equivalent
13-0 does equal 0
20. Not equivalent
12-2 doesn’t not equal 7-3
For all three of these equations you have to use PEMDAS (systems of equations) so first you solve everything that’s in parentheses, then any exponents, followed by multiplication,division,addition, and lastly subtraction. You MUST follow that order to get the correct answer.