| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.82 |
| Score | 0% | 56% |
Find the value of c:
-5c + x = 9
-7c + 3x = -3
| \(\frac{16}{73}\) | |
| -\(\frac{48}{59}\) | |
| -\(\frac{11}{12}\) | |
| -3\(\frac{3}{4}\) |
You need to find the value of c so solve the first equation in terms of x:
-5c + x = 9
x = 9 + 5c
then substitute the result (9 - -5c) into the second equation:
-7c + 3(9 + 5c) = -3
-7c + (3 x 9) + (3 x 5c) = -3
-7c + 27 + 15c = -3
-7c + 15c = -3 - 27
8c = -30
c = \( \frac{-30}{8} \)
c = -3\(\frac{3}{4}\)
The formula for the area of a circle is which of the following?
c = π d |
|
c = π r |
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c = π d2 |
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c = π r2 |
The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)2 : a = π r2.
When two lines intersect, adjacent angles are __________ (they add up to 180°) and angles across from either other are __________ (they're equal).
vertical, supplementary |
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obtuse, acute |
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acute, obtuse |
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supplementary, vertical |
Angles around a line add up to 180°. Angles around a point add up to 360°. When two lines intersect, adjacent angles are supplementary (they add up to 180°) and angles across from either other are vertical (they're equal).
If a = 6, b = 5, c = 1, and d = 2, what is the perimeter of this quadrilateral?
| 22 | |
| 18 | |
| 25 | |
| 14 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 6 + 5 + 1 + 2
p = 14
If a = -8 and x = -3, what is the value of -5a(a - x)?
| 56 | |
| -30 | |
| 72 | |
| -200 |
To solve this equation, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)
-5a(a - x)
-5(-8)(-8 + 3)
-5(-8)(-5)
(40)(-5)
-200