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Need help with polynomials multiplyingCould you help with Number 6 and 7

Need help with polynomials multiplyingCould you help with Number 6 and 7-example-1

1 Answer

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We are given the following polynomial


(x+3)(3x-1)(x-5)_{}

Let us multiply and simplify the polynomial.

First, multiply any two parentheses and simplify


(x+3)(3x-1)(x-5)_{}=(x\cdot3x+x\cdot-1+3\cdot3x+3\cdot-1)(x-5)_{}=(3x^2-x+9x-3)(x-5)=(3x^2+8x-3)(x-5)

Now, multiply the remaining two parentheses


(3x^2+8x-3)(x-5)=3x^2\cdot x+3x^2\cdot-5+8x\cdot x+8x\cdot-5-3\cdot x-3\cdot-5=3x^3-15x^2+8x^2-40x-3x+15=3x^3-7x^2-43x+15

Therefore, the expanded polynomial is


3x^3-7x^2-43x+15

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