The rationals being closed under subtraction means that if we start with two rational numbers and subtract them, we get another rational number. Choice c subtracts two rational numbers but gets the wrong answer, so isn't support for anything. Choice b is rational too because the square root of 4 is 2.
Answer: b
Go to the number next to the one you cannot subtract from, take one away, and add a one in front of the number you cannot subtract from. e.g.
27 1(1)7 the answer would be 9
-8 -8
for your problem the answer would be 1109
When height turns to 3 times height or 3h
we can replace h with 3h and see what happens
A=1/2b(3h)
A=3/2bh
A=3(1/2bh)
well, the area is trippled
Answer: C
<u>Step-by-step explanation:</u>
∑ 8(
)⁽ⁿ⁻¹⁾ from n = 1 to n = 5
n = 1 → 8(
)⁽¹⁻¹⁾
= 8 = 
n = 2 → 8(
)⁽²⁻¹⁾
=
=
n = 3 → 8(
)⁽³⁻¹⁾
=
= 
n = 4 → 8(
)⁽⁴⁻¹⁾
=
= 
n = 5 → 8(
)⁽⁵⁻¹⁾
=
= 
Sum = 
= 408.99
Answer:
the perimeter is 87
Step-by-step explanation: