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Co efficient of x^2 in (2-x) (5-3x) (1-7x)

User Qwadrox
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1 Answer

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Answer:

+ 80

Explanation:

Given

(2 - x)(5 - 3x)(1 - 7x) ← expand the first two factors using FOIL

= (10 - 11x + 3x²)(1 - 7x)

Each term in the second factor is multiplied by each term in the first factor

= 10(1 - 7x) - 11x(1 - 7x) + 3x²(1 - 7x) ← distribute the 3 parenthesis

= 10 - 70x - 11x + 77x² + 3x² - 21x³ ← collect like terms

= - 21x³ + 80x² - 81x + 10

The coefficient of the x² term is + 80

User Uros K
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