SOLUTION: Please help me solve this equation{{{a^2 + 4a - 21 = 0}}}

SOLUTION: Please help me solve this equation{{{a^2 + 4a - 21 = 0}}}

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Question 72822: Please help me solve this equation
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
First we need to know what 2 numbers add to 4 and multiply to -21: these two are 7 and -3. So the equation looks like this

The previous equation is factored into this. Now you can solve for a

So the solutions are a=-7 and a=3
Check:
Let a=-7

Works

Works
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