Q. Rewrite the expression as a product of four linear factors:(4x2+x)2−19(4x2+x)+70Answer:
Identify Expression: Let's identify the expression we need to factor: 4x^2 + x)^2 - 19(4x^2 + x) + 70\. This is a quadratic in form, with the "variable" being \$4x^2 + x)\. Let's set \$u = 4x^2 + x to simplify the expression.
Substitute Variable: Substitute u into the expression to see the quadratic form more clearly: u2−19u+70.
Factor Quadratic Expression: Now we need to factor the quadratic expression u2−19u+70. We are looking for two numbers that multiply to 70 and add up to −19. These numbers are −14 and −5 because (−14)×(−5)=70 and (−14)+(−5)=−19.
Write Factored Form: We can now write the factored form of the quadratic as (u−14)(u−5).
Substitute Back for u: Substitute back 4x2+x for u to get the factored form in terms of x: (4x2+x−14)(4x2+x−5).
Factor Quadratic Expression Further: Now we need to factor each quadratic expression further. Let's start with 4x2+x−14. We are looking for two numbers that multiply to −56 (4×−14) and add up to 1. These numbers are 8 and −7 because (8)×(−7)=−56 and 8+(−7)=1.
Write Factored Form: We can now write the factored form of 4x2+x−14 as (4x−7)(x+2).
Factor Quadratic Expression Further: Next, we factor 4x2+x−5. We are looking for two numbers that multiply to −20 (4×−5) and add up to 1. These numbers are 5 and −4 because (5)×(−4)=−20 and 5+(−4)=1.
Write Factored Form: We can now write the factored form of 4x2+x−5 as (4x−5)(x+1).
Combine Linear Factors: Finally, we combine all the linear factors to express the original expression as a product of four linear factors: 4x−7(x+2)(4x−5)(x+1).
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