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43 votes
43 votes
Solve x2 + 4x + 3 = 0 by completing the square.

options:
–6, –1
–3, –1
1, 3
–6, –2

User Echristo
by
2.5k points

2 Answers

27 votes
27 votes
Standard form:
X^2 +4x +3=0

Factorization:
(x+3=0)(x+1)=0

Solution based on top factorization:
X+3=0. X1= -3
X+1=0. X2= -1
User Alex Hart
by
2.4k points
15 votes
15 votes

Answer:

-3,-1

Explanation:

x²+4x+3=0

x²+4x=-3

x²+4x+(2)²=-3+(2)²

(x+2)²=-3+4

(x+2)²=1

Take square root of both sides

x+2=±1

x=-2±1

x=-1 or-3

User Bruce Edge
by
3.2k points