| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.16 |
| Score | 0% | 63% |
Solve for x:
7x - 4 > -5 - x
| x > -1\(\frac{3}{5}\) | |
| x > -\(\frac{7}{8}\) | |
| x > \(\frac{3}{8}\) | |
| x > -\(\frac{1}{8}\) |
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.
7x - 4 > -5 - x
7x > -5 - x + 4
7x + x > -5 + 4
8x > -1
x > \( \frac{-1}{8} \)
x > -\(\frac{1}{8}\)
If side a = 5, side b = 8, what is the length of the hypotenuse of this right triangle?
| \( \sqrt{89} \) | |
| \( \sqrt{13} \) | |
| \( \sqrt{50} \) | |
| \( \sqrt{61} \) |
According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:
c2 = a2 + b2
c2 = 52 + 82
c2 = 25 + 64
c2 = 89
c = \( \sqrt{89} \)
If the area of this square is 49, what is the length of one of the diagonals?
| 8\( \sqrt{2} \) | |
| 4\( \sqrt{2} \) | |
| \( \sqrt{2} \) | |
| 7\( \sqrt{2} \) |
To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:
a = s2
so the length of one side of the square is:
s = \( \sqrt{a} \) = \( \sqrt{49} \) = 7
The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:
c2 = a2 + b2
c2 = 72 + 72
c2 = 98
c = \( \sqrt{98} \) = \( \sqrt{49 x 2} \) = \( \sqrt{49} \) \( \sqrt{2} \)
c = 7\( \sqrt{2} \)
Solve for b:
b2 - 12b + 27 = 0
| 3 or 9 | |
| 8 or -9 | |
| 2 or -2 | |
| -2 or -5 |
The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:
b2 - 12b + 27 = 0
(b - 3)(b - 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b - 3) or (b - 9) must equal zero:
If (b - 3) = 0, b must equal 3
If (b - 9) = 0, b must equal 9
So the solution is that b = 3 or 9
What is 9a4 - 6a4?
| 54a4 | |
| 15a8 | |
| 3a4 | |
| 3a8 |
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.
9a4 - 6a4 = 3a4