| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.15 |
| Score | 0% | 63% |
Solve for c:
c - 2 = \( \frac{c}{2} \)
| -\(\frac{3}{14}\) | |
| -2\(\frac{1}{3}\) | |
| -\(\frac{36}{47}\) | |
| 4 |
To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the equal sign and the answer on the other.
c - 2 = \( \frac{c}{2} \)
2 x (c - 2) = c
(2 x c) + (2 x -2) = c
2c - 4 = c
2c - 4 - c = 0
2c - c = 4
c = 4
c = \( \frac{4}{1} \)
c = 4
Which of the following statements about math operations is incorrect?
you can multiply monomials that have different variables and different exponents |
|
you can add monomials that have the same variable and the same exponent |
|
you can subtract monomials that have the same variable and the same exponent |
|
all of these statements are correct |
You can only add or subtract monomials that have the same variable and the same exponent. For example, 2a + 4a = 6a and 4a2 - a2 = 3a2 but 2a + 4b and 7a - 3b cannot be combined. However, you can multiply and divide monomials with unlike terms. For example, 2a x 6b = 12ab.
The dimensions of this cylinder are height (h) = 4 and radius (r) = 1. What is the surface area?
| 10π | |
| 14π | |
| 84π | |
| 224π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(12) + 2π(1 x 4)
sa = 2π(1) + 2π(4)
sa = (2 x 1)π + (2 x 4)π
sa = 2π + 8π
sa = 10π
Which of the following is not a part of PEMDAS, the acronym for math order of operations?
division |
|
exponents |
|
addition |
|
pairs |
When solving an equation with two variables, 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.)
Solve for b:
b2 - 16b + 63 = 0
| -4 or -8 | |
| -2 or -7 | |
| 7 or 9 | |
| 8 or -6 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
b2 - 16b + 63 = 0
(b - 7)(b - 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b - 7) or (b - 9) must equal zero:
If (b - 7) = 0, b must equal 7
If (b - 9) = 0, b must equal 9
So the solution is that b = 7 or 9