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 Question from Jordan, a student: How do I solve the equation: 3(x+4)(x-6) Thanks for your help!

Hi Jordan,

The subject line of the email you sent indicated that you want to expand this expression. I am going to illustrate using a different expression.

Expand $5(x + 2)(x - 5)$

First of all I am going to ignore the 5 and expand $(x + 2)( x - 5).$ This I would do using the distributive law.

$(x + 2)( x - 5) = x(x - 5) + 2(x - 5).$

Expand and simplifying yields

$x(x - 5) + 2(x - 5) = x^2 - 5 x + 2 x + 2 \times -5 = x^2 - 3x - 10.$

Now we need to include the 5 we ignored so my solution is

$5(x + 2)( x - 5) = 5(x^2 - 3x - 10) = 5x^2 - 15x - 50.$