| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.24 |
| Score | 0% | 65% |
Solve for c:
-9c + 2 = \( \frac{c}{7} \)
| -\(\frac{7}{11}\) | |
| 1\(\frac{1}{5}\) | |
| -1\(\frac{8}{73}\) | |
| \(\frac{7}{32}\) |
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.
-9c + 2 = \( \frac{c}{7} \)
7 x (-9c + 2) = c
(7 x -9c) + (7 x 2) = c
-63c + 14 = c
-63c + 14 - c = 0
-63c - c = -14
-64c = -14
c = \( \frac{-14}{-64} \)
c = \(\frac{7}{32}\)
Simplify 2a x 4b.
| 8a2b2 | |
| 6ab | |
| 8ab | |
| 8\( \frac{a}{b} \) |
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.
2a x 4b = (2 x 4) (a x b) = 8ab
If a = 3, b = 5, c = 3, and d = 7, what is the perimeter of this quadrilateral?
| 18 | |
| 20 | |
| 10 | |
| 25 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 3 + 5 + 3 + 7
p = 18
If angle a = 59° and angle b = 68° what is the length of angle d?
| 143° | |
| 129° | |
| 130° | |
| 121° |
An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:
d° = b° + c°
To find angle c, remember that the sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 59° - 68° = 53°
So, d° = 68° + 53° = 121°
A shortcut to get this answer is to remember that angles around a line add up to 180°:
a° + d° = 180°
d° = 180° - a°
d° = 180° - 59° = 121°
Solve for y:
y2 - 19y + 54 = -4y - 2
| 8 or 7 | |
| 3 or -8 | |
| 7 or 8 | |
| 7 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:
y2 - 19y + 54 = -4y - 2
y2 - 19y + 54 + 2 = -4y
y2 - 19y + 4y + 56 = 0
y2 - 15y + 56 = 0
Next, factor the quadratic equation:
y2 - 15y + 56 = 0
(y - 7)(y - 8) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (y - 7) or (y - 8) must equal zero:
If (y - 7) = 0, y must equal 7
If (y - 8) = 0, y must equal 8
So the solution is that y = 7 or 8