Grade 8 Maths Exponents (Part A)

Answer explanation

To find the value of (2/5)^(-3), we reciprocate the fraction and change the exponent sign. This gives us (5/2)^3 = 125/8.

• 12

• 81

Answer explanation

The value of (-3)^{-4} is equal to 1/(-3)^4 which simplifies to 1/81, making the correct answer choice rac{1}{81}.

• -32

• 32

Answer explanation

The correct value is -1/32 because a negative base raised to a negative exponent results in the reciprocal of the positive base raised to the positive exponent.

Answer explanation

When dividing with the same base, subtract the exponents: 2^(-5) / 2^(-2) = 2^(-5 - (-2)) = 2^(-3) = 1/8

Answer explanation

To simplify the expression, we first find the sum of the reciprocals of 3 and 4, then take the reciprocal of that sum. Finally, divide by the reciprocal of 5. This simplifies to 7/60, which is equivalent to 60/7.

• 29

Answer explanation

To simplify the expression, we calculate the reciprocals of the fractions and then square them. This results in 4+9+16=29.

Answer explanation

To simplify the expression, first calculate the values inside the brackets, then divide by the value outside the brackets. This results in (27-8)/64 = 19/64.

• 16

• -16

Answer explanation

To solve the expression, start by evaluating the innermost parentheses: (-1/2)^2 = 1/4. Then, raise 1/4 to the power of -2 to get 16. Finally, raise 16 to the power of -1 to get 1/16, which is the correct answer.

• -1

• 1

• 2

• 3

Answer explanation

To solve the equation, use the property of exponents: add the exponents when multiplying the same base. Therefore, 3x + (-4) = 5, which simplifies to 3x = 9, and x = 3. Hence, the correct answer is 3.

• -2

• 0

• 1

• 2

Answer explanation

To find x, first solve the equation: (2^(3x-1) + 10) / 7 = 6. Simplify to get 2^(3x-1) + 10 = 42. Then solve for x to get x = 2.