<span>4x^2 - 36 = 0 ( Original equation )
4x^2 = 36 ( Add 36 to both sides )
x^2 = 9 ( Divide by 4 on both sides )
x = 3 , -3 ( Take the square root of 9 )
Solution set: { +3 , -3 } answer is x = +3 , x = -3</span>
Answer:
$12.49
Step-by-step explanation:
The price right now = 0.8 * the original price
9.99 = 0.8*x
x=12.4875
x≈12.49
Sorry, I thought your problem meant that it was 20% the original price, not 20% off.
Taking into consideration that the interest is compound (yearly)
the amount of money gather through the years can be calculated by
A = P (1+r)^(t)
6000 = 5000 (1.03)^t
t = ln(6000/5000)/ln(1.03) = 6.16 ≈ 7
c. 7 years
.45 Answer answer answer answer
