| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.73 |
| Score | 0% | 55% |
Solve -6c + 5c = -2c + 5z + 7 for c in terms of z.
| 2z - 2 | |
| 2z - \(\frac{1}{2}\) | |
| z - 1\(\frac{3}{4}\) | |
| -\(\frac{5}{6}\)z + \(\frac{1}{3}\) |
To solve this equation, isolate the variable for which you are solving (c) on one side of the equation and put everything else on the other side.
-6c + 5z = -2c + 5z + 7
-6c = -2c + 5z + 7 - 5z
-6c + 2c = 5z + 7 - 5z
-4c = + 7
c = \( \frac{ + 7}{-4} \)
c = \( \frac{}{-4} \) + \( \frac{7}{-4} \)
c = z - 1\(\frac{3}{4}\)
If the area of this square is 36, what is the length of one of the diagonals?
| 4\( \sqrt{2} \) | |
| 6\( \sqrt{2} \) | |
| 3\( \sqrt{2} \) | |
| 5\( \sqrt{2} \) |
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 = \( \sqrt{a} \) = \( \sqrt{36} \) = 6
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 = 62 + 62
c2 = 72
c = \( \sqrt{72} \) = \( \sqrt{36 x 2} \) = \( \sqrt{36} \) \( \sqrt{2} \)
c = 6\( \sqrt{2} \)
Simplify (4a)(8ab) - (4a2)(2b).
| 40ab2 | |
| 24a2b | |
| 72a2b | |
| 72ab2 |
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.
(4a)(8ab) - (4a2)(2b)
(4 x 8)(a x a x b) - (4 x 2)(a2 x b)
(32)(a1+1 x b) - (8)(a2b)
32a2b - 8a2b
24a2b
Which of the following is not true about both rectangles and squares?
the perimeter is the sum of the lengths of all four sides |
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the area is length x width |
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the lengths of all sides are equal |
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all interior angles are right angles |
A rectangle is a parallelogram containing four right angles. Opposite sides (a = c, b = d) are equal and the perimeter is the sum of the lengths of all sides (a + b + c + d) or, comonly, 2 x length x width. The area of a rectangle is length x width. A square is a rectangle with four equal length sides. The perimeter of a square is 4 x length of one side (4s) and the area is the length of one side squared (s2).
Solve for a:
7a - 3 = \( \frac{a}{-1} \)
| \(\frac{4}{29}\) | |
| \(\frac{3}{8}\) | |
| \(\frac{18}{19}\) | |
| -\(\frac{12}{17}\) |
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 equal sign and the answer on the other.
7a - 3 = \( \frac{a}{-1} \)
-1 x (7a - 3) = a
(-1 x 7a) + (-1 x -3) = a
-7a + 3 = a
-7a + 3 - a = 0
-7a - a = -3
-8a = -3
a = \( \frac{-3}{-8} \)
a = \(\frac{3}{8}\)