Question

Need help. Please and thank u

Answer 1

1)

(x + 3)(x + 4) = x^2 + 4x + 3x + 12 = x^2 + 7x + 12

Instead of multiplying 3 and 4 the student added them which gave them the answer of 7 when the correct answer is 12.

2)

a) x^2 + x - 2

b) x^2 - 7x + 10

c) 4x^2 - 1

d) x^2 + 10x + 25

Explanation:

a. (x - 1)(x + 2)

x(x) - 1(x) + 2(x) - 1(2)

x^2 - 1x + 2x - 2

x^2 + x - 2

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b. (x - 5)(x - 2)

x(x) - 5(x) - 2(x) - 5(-2)

x^2 - 5x - 2x + 10

x^2 - 7x + 10

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c. (2x + 1)(2x - 1)

2x(2x) + 1(2x) - 1(2x) + 1(-1)

4x^2 + 2x - 2x - 1

4x^2 - 1

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d. (x + 5)^2

(x + 5)(x + 5)

x(x) + 5(x) + 5(x) + 5(5)

x^2 + 5x + 5x + 25

x^2 + 10x + 25