We know the rule of change: a b/c= (ac+b):c
So we have 2 7/8= (2x8+7):8= 23/8
and the second: 2 1/4 = (2x4+1):4= 9/4
We do the division: 23/8: 9/4= 23/8 x 4/9= (23x4):(8x9)= 23/18= 1 5/18
You can factorize to simplify the expression
The answer would be,

Hope this helped
:D
Answer:
45
Step-by-step explanation:
Given
3z² - 6z ← substitute z = 5 into the expression
= 3(5)² - 6(5)
= 3(25) - 30
= 75 - 30
= 45
1) Would be c+15 because you can combine 19-4
2) Would be m+2 because you can combine 12-10