Remember P.E.M.D.A.S
57 - 12 ÷ 4 · 3
= 57 - 3 · 3
= 57 - 9
= 48
Expression 1 is 25
6*7-3^2*9+4^3
First simplify all the exponents to get 6*7 - 9 * 9 + 64 and then multiply the two numbers to get 42 - 81 + 64 and just add = 25
For expression 2, if you put the parantheses around (5+4)*2+6-2*2-1, it'll be 19
(5+4)*2+6-2*2-1
9*2+6-2*2-1
18+6-4-1
24-5
19
Remember order of operations
3x+15= 5x
8y-72= 9y
9a+18= 2a
3b-27= 9b
5c+40= 8c
6c+18= 3c
8c-8= c/1c
5x-10= 2x
2b-16= 8b
7c-35= 5c
