Alicia borrowed $15,000 to buy a car. She borrowed the money at 8% for 6 years. What is the interest she will pay for the loan ?
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Explanation:
Step-by-step clarification:
Referring to step 6
(b² — 4ac) / 4a² = (x + b/2a)²
The mistake in the question is that it should be (x + b/2a)²
According to step 7
±√(b² —4ac) /2a = x + b/2a
The error in the question is that it should be divided by 2a, not 1a.
1. The transition from step 6 to step 7 involves taking the square roots of both sides
(b² — 4ac) / 4a² = (x + b/2a)²
Taking the square of both sides
√(b²—4ac) / √4a² = √(x + b/2a)²
√(b²—4ac) / 2a = x + b/2a
This forms step 7 correctly.
Next, subtracting b/2a from both sides
√(b²—4ac) / 2a - b/2a= x + b/2a -b/2a
√(b²—4ac) / 2a — b/2a = x
(√(b²—4ac) — b)/2a = x
x = [—b ± √(b²—4ac)] / 2a
This gives the desired formula.
The discriminant is D = b²—4ac.
