SOLUTION: Section 10.2 Solve each equation using the quadratic formula. 10. x2 + 4x + 3 = 0

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: Section 10.2 Solve each equation using the quadratic formula. 10. x2 + 4x + 3 = 0       Log On


   

Question 171774: Section 10.2
Solve each equation using the quadratic formula.
10. x2 + 4x + 3 = 0
Found 2 solutions by nerdybill, jim_thompson5910:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
Your first course of solving a quadratic is the try and "factor", failing that, you can always resort to the "quadratic equation" (a little more time-consuming).
.
x^2 + 4x + 3 = 0
.
This one you can factor:
(x+3) (x+1) = 0
.
Setting each of the terms on the left to zero and solving for x yields:
x = {-3, -1}

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

x%5E2%2B4x%2B3=0 Start with the given equation.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=1, b=4, and c=3


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%284%29+%2B-+sqrt%28+%284%29%5E2-4%281%29%283%29+%29%29%2F%282%281%29%29 Plug in a=1, b=4, and c=3


x+=+%28-4+%2B-+sqrt%28+16-4%281%29%283%29+%29%29%2F%282%281%29%29 Square 4 to get 16.


x+=+%28-4+%2B-+sqrt%28+16-12+%29%29%2F%282%281%29%29 Multiply 4%281%29%283%29 to get 12


x+=+%28-4+%2B-+sqrt%28+4+%29%29%2F%282%281%29%29 Subtract 12 from 16 to get 4


x+=+%28-4+%2B-+sqrt%28+4+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-4+%2B-+2%29%2F%282%29 Take the square root of 4 to get 2.


x+=+%28-4+%2B+2%29%2F%282%29 or x+=+%28-4+-+2%29%2F%282%29 Break up the expression.


x+=+%28-2%29%2F%282%29 or x+=++%28-6%29%2F%282%29 Combine like terms.


x+=+-1 or x+=+-3 Simplify.


So the answers are x+=+-1 or x+=+-3