| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.31 |
| Score | 0% | 66% |
If side x = 15cm, side y = 11cm, and side z = 10cm what is the perimeter of this triangle?
| 25cm | |
| 36cm | |
| 16cm | |
| 32cm |
The perimeter of a triangle is the sum of the lengths of its sides:
p = x + y + z
p = 15cm + 11cm + 10cm = 36cm
A right angle measures:
90° |
|
360° |
|
45° |
|
180° |
A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.
What is 7a3 - 3a3?
| 21a6 | |
| 4a3 | |
| 4a6 | |
| 10a6 |
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.
7a3 - 3a3 = 4a3
Solve -6a + 9a = -7a - z + 7 for a in terms of z.
| -z - 1\(\frac{1}{4}\) | |
| 1\(\frac{1}{4}\)z + 2 | |
| -z - \(\frac{1}{4}\) | |
| -10z + 7 |
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.
-6a + 9z = -7a - z + 7
-6a = -7a - z + 7 - 9z
-6a + 7a = -z + 7 - 9z
a = -10z + 7
Solve for x:
x2 - 12x + 12 = -2x + 3
| 1 or 9 | |
| 4 or -4 | |
| 3 or -9 | |
| 1 or -1 |
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:
x2 - 12x + 12 = -2x + 3
x2 - 12x + 12 - 3 = -2x
x2 - 12x + 2x + 9 = 0
x2 - 10x + 9 = 0
Next, factor the quadratic equation:
x2 - 10x + 9 = 0
(x - 1)(x - 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (x - 1) or (x - 9) must equal zero:
If (x - 1) = 0, x must equal 1
If (x - 9) = 0, x must equal 9
So the solution is that x = 1 or 9