| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.26 |
| Score | 0% | 65% |
If a = 3, b = 2, c = 7, and d = 3, what is the perimeter of this quadrilateral?
| 15 | |
| 21 | |
| 14 | |
| 17 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 3 + 2 + 7 + 3
p = 15
Find the value of c:
4c + z = 3
7c - 5z = 2
| \(\frac{17}{27}\) | |
| \(\frac{4}{5}\) | |
| -2\(\frac{2}{3}\) | |
| -\(\frac{1}{2}\) |
You need to find the value of c so solve the first equation in terms of z:
4c + z = 3
z = 3 - 4c
then substitute the result (3 - 4c) into the second equation:
7c - 5(3 - 4c) = 2
7c + (-5 x 3) + (-5 x -4c) = 2
7c - 15 + 20c = 2
7c + 20c = 2 + 15
27c = 17
c = \( \frac{17}{27} \)
c = \(\frac{17}{27}\)
A cylinder with a radius (r) and a height (h) has a surface area of:
4π r2 |
|
2(π r2) + 2π rh |
|
π r2h2 |
|
π r2h |
A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The volume of a cylinder is π r2h and the surface area is 2(π r2) + 2π rh.
What is 8a + 2a?
| 6 | |
| a2 | |
| 10a | |
| 10a2 |
To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.
8a + 2a = 10a
Solve for c:
c2 - 2c - 15 = 0
| -3 or 5 | |
| 8 or 5 | |
| -2 or -3 | |
| 6 or -5 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
c2 - 2c - 15 = 0
(c + 3)(c - 5) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 3) or (c - 5) must equal zero:
If (c + 3) = 0, c must equal -3
If (c - 5) = 0, c must equal 5
So the solution is that c = -3 or 5