When a number x is added to its square, the total is 12. How do you find two possible values for x?

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Answer 1 · 2018-04-10T23:15:50

#x=-3, 4#

#x^2+x=12 rarr# Subtract 12 from each side

#x^2+x-12 rarr# This equation is in standard form: #ax^2+bx+c#

To solve this, we can graph, use the quadratic formula, or use the "big X" method (I'll use the third)

Think of two numbers that multiply to #c# (in this case, -12) and add up to #a*b# (in this case, 1): #-3 and 4#

#(x-3)(x+4)=0#

#x-3=0#

#x=3#

#x+4=0#

#x=-4#