Question

Evaluate each expression for s=4 and t=8
1) (25)^2t
2) 2st^2-5^2
3) 2s^2-t^3/16

Answer 1

1. 2.328×
`10^(22)`

2. 487

3. 30.52 OR 0 (see explanation↓)

Explanation:

1.
`(25)^(2t)`

(sub for t=8)

=
`25^(2*8)`

=
`25^(16)`

=2.328×
`10^(22)`

2.
`2st^(2) -5^(2)`

(sub for s=4 and t=8)

=2×4×
`8^(2)`-
`5^(2)`

=512-25

=487

3.
`2s^(2) -t^(3/16)` (the equation is not clear so I will do
`2s^(2) -(t^(3) )/(16)` as well)

FOR
`2s^(2) -t^(3/16)`

(sub s=4 and t=8)

=2×
`4^(2)`-
`8^(3/16)`

=32-1.476826146

=30.52 (to the nearest 2 decimal place)

FOR
`2s^(2) -(t^(3) )/(16)`

(sub s=4 and t=8)

=2×
`4^(2)`-
`(8^(3) )/(16)`

=32-32

=0