Answer:
x = 3/2 or x = -5/4
Step-by-step explanation:
Solve for x over the real numbers:
8 x^2 - 2 x - 15 = 0
Using the quadratic formula, solve for x.
x = (2 ± sqrt((-2)^2 - 4×8 (-15)))/(2×8) = (2 ± sqrt(4 + 480))/16 = (2 ± sqrt(484))/16:
x = (2 + sqrt(484))/16 or x = (2 - sqrt(484))/16
Simplify radicals.
sqrt(484) = sqrt(4×121) = sqrt(2^2×11^2) = 2×11 = 22:
x = (2 + 22)/16 or x = (2 - 22)/16
Evaluate (2 + 22)/16.
(2 + 22)/16 = 24/16 = 3/2:
x = 3/2 or x = (2 - 22)/16
Evaluate (2 - 22)/16.
(2 - 22)/16 = -20/16 = -5/4:
Answer: x = 3/2 or x = -5/4
A = P + I
2a = a + PTR/100
2a = a + 5aT/100
2a = a(1+T/20)
2=1+T/20
T=20 yrs
It will take 6 years for that to happen.
You can find this by setting Nichole's age as x and Sophie's age as x + 28 since she will always be 28 years older.
Now we are looking for a time that Sophie's age is equal to 2 less than 6 times Nichole's age. So we can set up the below equation.
6(x) - 2 = x + 28
6x - 2 = x + 28
5x - 2 = 28
5x = 30
x = 6
This let's us know that it needs to be when Nichole is 6, which is 6 years in the future.
