<span><span>x = x^2 - 30
or
x^2 - x - 30 = 0
Factors to
(x-6)(x+5) = 0
x = +6 is the positive number</span></span>
The final price is the cost plus the tax.
Since we know the tax and a percent, we can write this as
T = C(1+r)
T = what Graham paid = $87.45
C = cost before tax
r = tax rate expressed as a decimal = .40
Plugging in what we know
87.45 = C (1+.4)
87.45 = C(1.4)
Divide both sides by 1.4
C = $62.46
Answer:
(-10)² = -10 x -10 = 100
- 10² = - (10 x 10) = - 100
Step-by-step explanation:
(-10)² = -10 x -10 = 100
- 10² = - (10 x 10) = - 100
