Algebra sample problem question – Khan Academy Help Center

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Roger Pattie

July 07, 2017 17:03

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In the equation y=3(x+5)(x-2), when combining the factors on the right side, do you have to deal with x squared at any point when solving for y?

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Austin Ho

July 08, 2017 00:34
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After solving the equation, you'll get y=3x^2+9x-30. That'd be the simplified equation and you don't have to do anything.

I'm assuming that you mean solving for x when y=0? Then there'd be a different way of solving this by either using your above equation and setting each parenthetical element equal to 0 (0=x+5, x=-5; OR 0=x-2, x=2) or using the quadratic formula.

Hopefully I helped, and please ping me if I didn't answer your question. Good luck!
boruto

August 18, 2017 06:22
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y=3(x+5)(x-2)
y=3x^2+9x-30( the equation is a qudratic equation )
(x=-b±√b^2-4ac÷2a formula )
(a=3 b=9c=30 values)
solve the equation find value of x put it in question find y
best of luck Roger pattle

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