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Simple Math Help, Please! Simplify? y'= 20(5x − 1)^3(7x^2 − 1)^−3 − 42x(5x − 1)^4(7x^2 − 1)^−4?

I am having trouble simplifying this expression. Can someone show me step by step?

y′ = 4(5x − 1)^3(5)(7x^2 − 1)^−3 + (5x − 1)^4(−3)(7x^2 − 1)^−4(14x)

y'= 20(5x − 1)^3(7x^2 − 1)^−3 − 42x(5x − 1)^4(7x^2 − 1)^−4

1 Answer

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  • 6 years ago
    Favorite Answer

    Some further symbols of inclusion would've been helpful; I'll assume you mean:

    y' = (20)[(5x-1)^3][(7x^2-1)^(-3)] - (42x)[(5x-1)^4][(7x^2-1)^(-4)].

    I would rewrite it as:

    y' = [(5x-1)^3][(7x^2-1)^(-4)] [(20)(7x^2-1) - (42x)(5x-1)]

    = [(5x-1)^3] [(7x^2-1)^(-4)] [140x^2 - 20 - 210x^2 + 42x]

    = [(42x - 20 - 70x^2)(7x^2 - 1)^4 ] / [(5x-1)^3],

    and I wouldn't try to go any farther than that.

    The first trinomial may be factorable,

    but its factors won't "cancel" anything.

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