Q. Rewrite the expression as a product of four linear factors:(x2−x)2−22(x2−x)+40Answer:
Identify Structure: Let's first identify the structure of the given expression and see if it resembles any known algebraic identities. The expression is:(x2−x)2−22(x2−x)+40This looks like a quadratic equation in the form of (a2−2ab+b2), where ′a′ is (x2−x) and ′b′ is some number we need to find. To factor it, we will consider it as a quadratic in terms of (x2−x).
Substitute and Simplify: Let's denote u=x2−x. Then the expression becomes:u2−22u+40Now we need to factor this quadratic expression.
Factor Quadratic Expression: To factor the quadratic expression u2−22u+40, we need to find two numbers that multiply to 40 and add up to −22. These numbers are −20 and −2 because (−20)×(−2)=40 and (−20)+(−2)=−22.So we can write the quadratic as:(u−20)(u−2)
Factor First Quadratic: Now we substitute back x2−x for u in the factored form to get:(x2−x−20)(x2−x−2)Now we need to factor each of these quadratic expressions further.
Factor Second Quadratic: We will factor the first quadratic expression x2−x−20. We need to find two numbers that multiply to −20 and add up to −1 (the coefficient of x). These numbers are −5 and 4 because (−5)×4=−20 and (−5)+4=−1.So we can write the first quadratic as:(x−5)(x+4)
Final Linear Factors: Next, we will factor the second quadratic expression x2−x−2. We need to find two numbers that multiply to −2 and add up to −1 (the coefficient of x). These numbers are −2 and 1 because (−2)×1=−2 and (−2)+1=−1.So we can write the second quadratic as:(x−2)(x+1)
Final Linear Factors: Next, we will factor the second quadratic expression x2−x−2. We need to find two numbers that multiply to −2 and add up to −1 (the coefficient of x). These numbers are −2 and 1 because (−2)×1=−2 and (−2)+1=−1.So we can write the second quadratic as:(x−2)(x+1)Now we have factored the original expression into four linear factors:(x−5)(x+4)(x−2)(x+1)This is the product of four linear factors for the given expression.
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