Answer: B, x = 2,-5
Step-by-step explanation:
Use the quadratic equation: [-b + or - the square root of (4*a*c)]/ 2a. In the square root part, the number will be negative, so you have to take out an imaginary number. The only answers with an imaginary number are B and A. The number under the square root is -31, so B is the answer.
Second question:
x^2 + 3x - 10 = 0
Find 2 numbers that add to 3 but multiply to 10. Those numbers would be -2 and 5.
(x - 2)(x + 5) = 0
Since it must equal zero, one of the parenthesis must equal to 0. Therefore, x = 2 or -5
