# How do you factor the trinomial #3x^2 + 12x + 7 #?

##### 1 Answer

Nov 21, 2015

To factor the trinomial, we use the quadratic formula to solve for the zeros, which are

#### Explanation:

Since there is no common factor between any of the three terms, we have to use the quadratic formula:

#x=(-b+-sqrt(b^2-4ac))/(2a)#

#x=(-(12)+-sqrt((12)^2-4(3)(7)))/(2(3))#

#x=(-12+-sqrt((144)-(84)))/6#

#x=(-12+-sqrt(60))/6#

#x=(-12+-2sqrt(15))/6#

#x=(2(-6+-1sqrt(15)))/(2(3))#

#x=(color(red)cancelcolor(black)(2)(-6+-1sqrt(15)))/(color(red)cancelcolor(black)(2)(3))#

#x=(-6+-sqrt(15))/(3)#

#x=-0.71# or#-3.29#

If your answer is supposed to be exact, your answer is:

#x=(-6+-sqrt(15))/(3)#

Otherwise, you can continue to solve for the approximate values of