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2. If f(x) = 2x2 – 7x -10, find the following: a) f(x-1) b) x, if f(x) = 5 Please helpppppp

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Answer:

a) f(x-1) = 2x^2-11x-1

b) x = -1.5 or 5

Explanation:

a) To get f(x-1)

We proceed to substitute x-1 for x as follows

f(x-1) = 2(x-1)^2 -7(x-1) -10

f(x-1) = 2(x^2 - 2x + 1) -7(x-1)-10

f(x-1) = 2x^2 -4x + 2 -7x + 7-10

f(x-1) = 2x^2-11x-1

b) What we have to do here is substitute 5 for f(x) and solve for x

5 = 2x^2 -7x-10

2x^2 -7x -10-5 = 0

2x^2 - 7x - 15 = 0

2x^2 -10x + 3x -15 = 0

2x(x-5) + 3(x-5) = 0

(2x + 3)(x-5) = 0

2x + 3 = 0 or x -5 = 0

2x = -3 or x = 5

x = -3/2 or x = 5

x = -1.5 or 5

User Mike Hordecki
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