| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.16 |
| Score | 0% | 63% |
Solve 9c + 10c = c - 9y + 4 for c in terms of y.
| -2\(\frac{4}{5}\)y + \(\frac{1}{5}\) | |
| -2\(\frac{3}{8}\)y + \(\frac{1}{2}\) | |
| \(\frac{3}{4}\)y + 1\(\frac{1}{2}\) | |
| 4y - 6 |
To solve this equation, isolate the variable for which you are solving (c) on one side of the equation and put everything else on the other side.
9c + 10y = c - 9y + 4
9c = c - 9y + 4 - 10y
9c - c = -9y + 4 - 10y
8c = -19y + 4
c = \( \frac{-19y + 4}{8} \)
c = \( \frac{-19y}{8} \) + \( \frac{4}{8} \)
c = -2\(\frac{3}{8}\)y + \(\frac{1}{2}\)
Simplify 9a x 8b.
| 72\( \frac{b}{a} \) | |
| 72ab | |
| 17ab | |
| 72a2b2 |
To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.
9a x 8b = (9 x 8) (a x b) = 72ab
The dimensions of this cylinder are height (h) = 4 and radius (r) = 7. What is the volume?
| 4π | |
| 729π | |
| 16π | |
| 196π |
The volume of a cylinder is πr2h:
v = πr2h
v = π(72 x 4)
v = 196π
If side x = 15cm, side y = 11cm, and side z = 12cm what is the perimeter of this triangle?
| 25cm | |
| 30cm | |
| 35cm | |
| 38cm |
The perimeter of a triangle is the sum of the lengths of its sides:
p = x + y + z
p = 15cm + 11cm + 12cm = 38cm
Solve for a:
a2 + 18a + 60 = 2a - 4
| 4 or 1 | |
| -8 | |
| -5 or -6 | |
| 9 or -2 |
The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:
a2 + 18a + 60 = 2a - 4
a2 + 18a + 60 + 4 = 2a
a2 + 18a - 2a + 64 = 0
a2 + 16a + 64 = 0
Next, factor the quadratic equation:
a2 + 16a + 64 = 0
(a + 8)(a + 8) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, (a + 8) must equal zero:
If (a + 8) = 0, a must equal -8
So the solution is that a = -8