| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.41 |
| Score | 0% | 68% |
If the base of this triangle is 9 and the height is 5, what is the area?
| 22\(\frac{1}{2}\) | |
| 77 | |
| 36 | |
| 35 |
The area of a triangle is equal to ½ base x height:
a = ½bh
a = ½ x 9 x 5 = \( \frac{45}{2} \) = 22\(\frac{1}{2}\)
Solve for a:
a2 + 7a + 4 = a - 1
| -1 or -5 | |
| -4 or -9 | |
| 9 or 6 | |
| 2 or -3 |
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 + 7a + 4 = a - 1
a2 + 7a + 4 + 1 = a
a2 + 7a - a + 5 = 0
a2 + 6a + 5 = 0
Next, factor the quadratic equation:
a2 + 6a + 5 = 0
(a + 1)(a + 5) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (a + 1) or (a + 5) must equal zero:
If (a + 1) = 0, a must equal -1
If (a + 5) = 0, a must equal -5
So the solution is that a = -1 or -5
If BD = 19 and AD = 27, AB = ?
| 11 | |
| 9 | |
| 8 | |
| 19 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDWhat is 8a + 4a?
| 4 | |
| 12a2 | |
| 12a | |
| 4a2 |
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 + 4a = 12a
A(n) __________ is two expressions separated by an equal sign.
equation |
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expression |
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formula |
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problem |
An equation is two expressions separated by an equal sign. The key to solving equations is to 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.