How do you solve 3m ^ { 2} - 5m - 7= - 5?

1 Answer
Jun 20, 2018

m=-1/3 or m=-2

Explanation:

3m^2-5m-7=-5
3m^2-5m-7+5=0
3m^2-5m-2=0

Using either the criss cross method or the quadratic formula, you would get the answer
(3m+1)(m-2)=0 so m=-1/3 or m=-2


Using the quadratic formula,

color (red) (m=(-b+-sqrt(b^2-4ac))/(2a) where your general form is given by am^2+bm+c=0

m=(5+-sqrt(25+24))/6

m=(5+-sqrt49)/6

m=(5+-7)/6

m=(5-7)/6 or m=(5+7)/6

m=-1/3 or m=2

(m-(-1/3))(m-2)=0

Which can then be put into the following form
(m+1/3)(m-2)=0

(3m+1)(m-2)=0