Factor the quadratic equation: First, we need to factor the quadratic equationx2+x−72=0.
Find suitable numbers: Looking for two numbers that multiply to −72 and add up to 1. After some trial and error, we find that 9 and −8 work because 9×−8=−72 and 9+(−8)=1.
Write the factored equation: So we can write the equation as (x+9)(x−8)=0.
Set each factor equal: Now, we set each factor equal to zero: x+9=0 or x−8=0.
Solve for x: Solving x+9=0 gives us x=−9.
Final solutions: Solving x−8=0 gives us x=8.
Final solutions: Solving x−8=0 gives us x=8.We found two values of x that satisfy the equation: x=−9 and x=8.
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