Answer:
first one
Step-by-step explanation:
Because the coefficient of x is 3 and coefficient of y is-7
The answer would be 24pi inches.
You can find this by using the formula for a circumference and plugging in the value of the radius.
C = 2pi*r
C = 2pi * 12
C = 24pi
Writing some equations out might help!
1) You know that a is 4/5 of b. This can be written as:

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To find what b is equal to, multiply both sides by 5/4:

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A is 5/4 B.
2) You know that a is 1/5 smaller than b. This can be written as:

.
To find b, just add 1/5 to both sides:

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B is 1/5 bigger than a.
<span>When 3 Triangle sides are known:
</span><span>The longest side must be less than the sum of the other 2 sides.
5, 12 and 13 - can be constructed
</span>2, 11 and 15 <span>- can be constructed
3, 7 and 11 - CAN'T be constructed - the longest side is greater than the sum of the other two.
4, 8 and 15 </span><span>- CAN'T be constructed - the longest side is greater than the sum of the other two
Source:
http://www.1728.org/trianinq.htm
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