You can think in reverse. Addition is the opposite of subtraction. So to solve 15-8, you can ask "8 plus what number is equal to 15?" and note how 8+7 = 15. So that's why 15-8 = 7. Similarly, 15-7 = 8 can be solved the same way.
Answer:
A tangent.
Step-by-step explanation:
Answer:
4a) 
· (5 + 7)
b) 3 ÷ (3/5)
c) ( - 
) ÷ 3
Step-by-step explanation:
Answer:
14(y + 2).
Step-by-step explanation:
32 +2/3(21y - 6)
Distributing the 2/3 over the parentheses:
= 32 + 2/3*21y + 2/3 * -6
= 32 + 14y - 4
= 14y + 28
= 14(y + 2).
That is so cool, thanks for the trick idea.
