Question

The formula A = P + Prt represents the value, A, of an investment of P dollars at a yearly simple interest rate, r, for t years. The equation to model the value, A, of an investment of $54 at 9.26% for t years is given by

A = 54 + 5t.

The equation to model the value, A, of an investment of $84 at 2.38% for t years is given by

A = 84 + 2t.

Assuming A has the same value, the given equations form a system of two linear equations. Solve this system using an algebraic approach and interpret your answer.

Answer 1

I have no Idea
a.
t = 5
The two investments will reach the same value in 5 years.
c.
t = 1000
The two investments will reach the same value in 1000 years.
b.
t = 20
The two investments will reach the same value in 20 years.
d.
t = 10
The two investments will reach the same value in 10 years.

Answer 2

Subtract the first equation from the second. The A's cancel out.

Answer 3

3t = 84-54.

Answer 4

then divide by 3? @primeralph

Answer 5

Of course.

Answer 6

Thanks!