Answer:
18
Step-by-step explanation:
7 - 5 = 2
triangle = bh/2
triangle = 2(3) / 2
triangle = 3
rect = bh
rect = 3 x 5
rect = 15
trapezoid = 15 + 3
trapezoid = 18
When applying indirect proofs, we assume the negation of the conclusion is true, and show that this assumption would lead to nonsense, or contradiction.
In our case we assume a is not smaller than 7, that is we assume a≥7.
a≥7 then, multiplying both sides by 3:
3a≥21, then, adding both sides 7:
3a+7≥28,
which is a contradiction because 3a+7 is smaller than 28.
So our assumption is wrong, which means the opposite of it is correct.
Answer: assume a≥7
Subtract 8/10 from 4/10 but just the numerator (the top number) and you will get 4/10
