Question

Evaluate each expression for x = 4 and give answers in simplest form. Show your work

Answer 1

a)
`6x^(-2)  = (3)/(8)`

b)
`5x^(-3)  = (5)/(64)`

Explanation:

The value given for x is 4

1) The given expression is :
`6x^(-2)`

By solving the negative exponent, we get
`6x^(-2)  = (6)/(x^(2) )`

Here, substitute x =4,
`(6)/(x^(2) ) =  (6)/(4 * 4 )  =  (6)/(16)`

or,
`6x^(-2)  = (3)/(8)`

2) The given expression is :
`5x^(-3)`

By solving the negative exponent, we get
`5x^(-3)  = (5)/(x^(3) )`

Here, substitute x =4,
`(5)/(x^(3) ) =  (5)/(4 * 4 * 4 )  =  (5)/(64)`

or,
`5x^(-3)  = (5)/(64)`