In this problem, you're looking for the value of t, so that f(t) = 48. That means if you put t into 5t-7, you'll get 48. To do this set up and solve an equation for t by setting 48 equal to 5t-7:

Isolate the variable by adding 7 to both sides.

Divide by 5 on both sides to find t.

The answer is 11.
(4x20)+30=$110 taken out. if he had $96 put back in, then go $110-$96, leaving a balance of -$14, or in other words, the balance dropped $14.
Take the square root of 10,000, which is 100.
3 and 1 half is also known as 3.5,
3.5 x 3.5 = 12.25
in fractions that is 12 and 1 quarter
Interest rate = 7%
I= PRT where I is the interest earned, p is the principal, r is rate as a decimal, and t is time in years.
A - P will give us the interest earned.
12,150 - 9,000 = 3,150
3150 = (9000)(r)(5)
3150 = 45,000r
r = 0.07
r = 7%