Phone card = $20
You need to minus 17.92 from 20 = $2.08
$2.08 / 0.13 = how many minutes
= 16
Step-by-step explanation:
<h3>
Answer: 16</h3>
=============================================================
Explanation:
Equate s(t(x)) and s(1) to find that t(x) = 1 must be the case.
Let's find what x must be.
t(x) = 3x-8
1 = 3x-8
1+8 = 3x
9 = 3x
3x = 9
x = 9/3
x = 3
So plugging x = 3 into t(x) gets us t(x) = 1
In other words, t(3) = 1
So that tells us s(t(3)) = s(1)
-------------
Let's plug x = 3 into the s(t(x)) equation
s(t(x)) = x^2 + 3x - 2
s(t(3)) = (3)^2 + 3(3) - 2
s(1) = 9 + 3(3) - 2
s(1) = 9 + 9 - 2
s(1) = 18 - 2
s(1) = 16
20% = 20/100 = 1/5
1/5 of 3500
1/5 X 3500/1 = 3500/5
3500/5 = 700.
