| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.81 |
| Score | 0% | 56% |
Solve for a:
2a + 8 < \( \frac{a}{-2} \)
| a < 3\(\frac{3}{5}\) | |
| a < -9\(\frac{3}{5}\) | |
| a < -4 | |
| a < -3\(\frac{1}{5}\) |
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.
2a + 8 < \( \frac{a}{-2} \)
-2 x (2a + 8) < a
(-2 x 2a) + (-2 x 8) < a
-4a - 16 < a
-4a - 16 - a < 0
-4a - a < 16
-5a < 16
a < \( \frac{16}{-5} \)
a < -3\(\frac{1}{5}\)
Simplify (y + 5)(y - 8)
| y2 + 3y - 40 | |
| y2 - 13y + 40 | |
| y2 - 3y - 40 | |
| y2 + 13y + 40 |
To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:
(y + 5)(y - 8)
(y x y) + (y x -8) + (5 x y) + (5 x -8)
y2 - 8y + 5y - 40
y2 - 3y - 40
If the area of this square is 49, what is the length of one of the diagonals?
| 4\( \sqrt{2} \) | |
| 9\( \sqrt{2} \) | |
| 3\( \sqrt{2} \) | |
| 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\( \sqrt{2} \)
Simplify (3a)(5ab) - (5a2)(8b).
| 104a2b | |
| -25a2b | |
| 55a2b | |
| 104ab2 |
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.
(3a)(5ab) - (5a2)(8b)
(3 x 5)(a x a x b) - (5 x 8)(a2 x b)
(15)(a1+1 x b) - (40)(a2b)
15a2b - 40a2b
-25a2b
Find the value of c:
8c + x = -6
8c - 2x = 1
| \(\frac{1}{21}\) | |
| 1\(\frac{6}{19}\) | |
| -1\(\frac{3}{5}\) | |
| -\(\frac{11}{24}\) |
You need to find the value of c so solve the first equation in terms of x:
8c + x = -6
x = -6 - 8c
then substitute the result (-6 - 8c) into the second equation:
8c - 2(-6 - 8c) = 1
8c + (-2 x -6) + (-2 x -8c) = 1
8c + 12 + 16c = 1
8c + 16c = 1 - 12
24c = -11
c = \( \frac{-11}{24} \)
c = -\(\frac{11}{24}\)