Grade 7 Maths Exponents Quiz (Part A)

• -2

• 24

Answer explanation

To simplify the expression, we first find the values of 6^-1 and 8^-1, which are 1/6 and 1/8 respectively. Then, (1/6 - 1/8)^-1 = (4/24 - 3/24)^-1 = (1/24)^-1 = 24.

• 15

• -15

Answer explanation

(5^{-1}\times3^{-1})^{-1} = (\frac{1}{5}\times\frac{1}{3})^{-1} = \frac{1}{15} = 15

• 4

• -4

Answer explanation

(2^{-1}-4^{-1})^2 = (\frac{1}{2}-\frac{1}{4})^2 = (\frac{2-1}{4})^2 = (\frac{1}{4})^2 = \frac{1}{16}

• 29

• none of these

Answer explanation

To simplify the expression, we calculate the reciprocals first: (2)^2 + (3)^2 + (4)^2 = 4 + 9 + 16 = 29. Therefore, the correct answer is 29.

• none of these

Answer explanation

To simplify the expression, first find the values of the terms inside the brackets. Then calculate the sum and take the reciprocal to get the final answer, which is 6/5.

• -64

• 64

Answer explanation

To find the reciprocal of a number, flip the fraction. So, the reciprocal of -1/2 is -2/1 = -2. Then, raise -2 to the power of -1 to get 1/-2 = -1/2. Therefore, the answer is 64.

Answer explanation

To simplify the expression, first calculate the values inside the parentheses: (3/4)^{-1} = 4/3 and (1/4)^{-1} = 4. Then subtract to get 4/3 - 4 = -8/3. Finally, take the reciprocal to get -3/8.

• 16

Answer explanation

To simplify the expression, start from the innermost parentheses and work outward. (-1/2)^2 = 1/4. Then, (-1/4)^(-2) = 1/(1/4)^2 = 1/(1/16) = 16. Therefore, the answer is 1/16.

• 0

• 1

• none of these

Answer explanation

Any number raised to the power of 0 is always 1. Therefore, (5/6)^0 = 1. The correct choice is 1.

Answer explanation

(2/3)^{-5} = (3/2)^5 = 243/32