+1911 One root of the quadratic equation $x^2 + bx -28 = 4x + 14$ is $-7$. What is the value of $b$?
+37147 If - 7 is a root....putting in -7 for 'x' will result in the equation = 0 Putting all of the factors on the LEFT side:
x^2 + x ( b-4) -42 = 0
(-7)^2 + (-7) (b-4) - 42 = 0
49 - 7b + 28 - 42 = 0
35 = 7b
b = 5
