Question

What is the value of 10x^-3y^-1 for x=-1 and y=-3?

A. 10(3)^-4

B. 30

C. 10/81

D. 3 1/3

Answer 1

The correct answer is: [D]: " 3
`(1)/(3)` " .
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Step-by-step explanation:
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Given: " 10x⁻³ y⁻¹ " ;

Evaluate when: " x = -1 " ; and when " y = -3 " ;

→ 10 * (-1)⁻³ * (-3)⁻¹ = ?

Note: " (-1)⁻³ = (1 / (-1)³ = 1 / (-1 * -1 * -1) = 1/ -1 = -1 " ;

→ " (-1)⁻³ = -1 " ;

→ " (-3)⁻¹ = 1 / (-3)¹ = 1 / -3 ; = - 1/3 ;

→ " 10x⁻³ y⁻¹ = 10 * (-1) * ( - 1/3) ;

= -10 * (- 1/3) = (-10/1) * (-1/3) = (-10 * -1) / (1 * 3) = 10/3;

→ 10/3 = 10 ÷ 3 = " 3
`(1)/(3)` " ;
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→ which is: Answer choice: [D]: " 3
`(1)/(3)` " .
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