Answer:
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Step-by-step explanation:
Part A:
The circumference of the circle is 197.92.
Explanation:
The formula for circumference of a circle is C=2 πr. If you insert the numbers, it would be C=2 x 3.14 x 31.5. Hence, the answer is 197.92.
Part B:
The area is 3117.25 square cm.
Explanation:
The formula for area of a circle is A= πr ². Inserting the numbers, it is A=3.14 x 31.5 ². Therefore the answer is 3117.25 cm ².
The answer is C. . . . . . . . . . . . .
Given:
2x - 3y = -6 ⇒ identified as 1st equation
x + 2y = 8 ⇒ identified as 2nd equation
Let us first get the value of x using the 2nd equation.
x + 2y = 8
x = 8 - 2y
Substitute x in the 1st equation with its value and find the value of y.
2x - 3y = -6
2(8-2y) - 3y = -6
16 - 4y -3y = -6
-4y - 3y = -6 -16
-7y = - 22
y = -22/-7
y = 22/7 simplified to 3 1/7
Substitute the value of y in the 2nd equation.
x = 8 - 2y
x = 8 - 2(22/7)
x = 8 - 44/7
x = (8 * 7/7) - 44/7
x = 56/7 - 44/7
x = (56-44)/7
x = 12/7 simplified to 1 5/7
To check: x = 12/7 and y = 22/7 *we need to use the improper fractions.
2x - 3y = -6
2(12/7) - 3(22/7) = -6
24/7 - 66/7 = -6
(24-66)/7 = -6
-42/7 = -6
-6 = -6
x + 2y = 8
12/7 + 2(22/7) = 8
12/7 + 44/7 = 8
(12+44)/7 = 8
56/7 = 8
8 = 8
False because the left is statement in the right is reason
