One root of the quadratic equation $x^2 + bx -28 = 4x + 14$ is $-7$. What is the value of $b$?
+36916 x^2 + bx -28 = 4x + 14 Simplify to
x^2 + (b-4) x - 42 = 0 If - 7 is a root, puting in -7 for 'x' will result in this equation = 0
(-7)^2 + (b-4)(-7) - 42 = 0
49 - 7b + 28 - 42 = 0
35 - 7b = 0
b = 5
+36916 x^2 + bx -28 = 4x + 14 Simplify to
x^2 + (b-4) x - 42 = 0 If - 7 is a root, puting in -7 for 'x' will result in this equation = 0
(-7)^2 + (b-4)(-7) - 42 = 0
49 - 7b + 28 - 42 = 0
35 - 7b = 0
b = 5
