What is solution set of the equation: x2+ 4x + 3 =0

What is the solution set of the equation: x2+ 4x + 3 =0

(A) {1, 3}
(B) {–1, 3}
(C) {1, –3}
(D) {–1, –3}

Answer: (D) {–1, –3}

Solution: