| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.04 |
| Score | 0% | 61% |
What is 9a9 + 2a9?
| 11a9 | |
| 11a18 | |
| 7 | |
| 18a9 |
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.
9a9 + 2a9 = 11a9
Solve -4a + 6a = -5a + 8y - 1 for a in terms of y.
| -5y - 1\(\frac{1}{2}\) | |
| 2y - 1 | |
| \(\frac{11}{17}\)y + \(\frac{4}{17}\) | |
| -\(\frac{1}{4}\)y - \(\frac{1}{4}\) |
To solve this equation, isolate the variable for which you are solving (a) on one side of the equation and put everything else on the other side.
-4a + 6y = -5a + 8y - 1
-4a = -5a + 8y - 1 - 6y
-4a + 5a = 8y - 1 - 6y
a = 2y - 1
If side x = 9cm, side y = 9cm, and side z = 11cm what is the perimeter of this triangle?
| 30cm | |
| 29cm | |
| 34cm | |
| 38cm |
The perimeter of a triangle is the sum of the lengths of its sides:
p = x + y + z
p = 9cm + 9cm + 11cm = 29cm
If angle a = 31° and angle b = 64° what is the length of angle d?
| 114° | |
| 149° | |
| 127° | |
| 120° |
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° - 31° - 64° = 85°
So, d° = 64° + 85° = 149°
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° - 31° = 149°
Solve for b:
5b + 7 < 3 - 5b
| b < -\(\frac{2}{5}\) | |
| b < \(\frac{3}{4}\) | |
| b < -2\(\frac{1}{2}\) | |
| b < -2\(\frac{1}{4}\) |
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 < sign and the answer on the other.
5b + 7 < 3 - 5b
5b < 3 - 5b - 7
5b + 5b < 3 - 7
10b < -4
b < \( \frac{-4}{10} \)
b < -\(\frac{2}{5}\)