Question 310094
Use the following quadratic equation to complete parts a and b below. You must show all work. 
x2 + 4x - 21 = 0 
a. Solve by factoring.
(x+7)*(x-3) = 0
x = -7, 3
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b. Solve using the quadratic formula
*[invoke solve_quadratic_equation 1,4,-21]