How do you factor 6r² + 7r -10?

1 Answer
May 17, 2015

The answer is #(6r-5)(r+2)#

Problem: Factor #6r^2+7r-10# . The format of this equation is #ax+bx+c#.

Multiply #a*c#.

#6*-10=-60#.

Determine two numbers that when added make #b#, and when multiplied make #a*c#.

#b=7#; #a*c=-60#

The numbers #12# and #-5# fit the required pattern.

Rewrite the equation with #12r# and #-5r# in place of #7r# .

#6r^2+12r-5r-10#

Factor by grouping.

#(6r^2+12r)-(5r-10)#

Factor out common terms.

#6r(r+2)#

#-5(r+2)#

Factor out the common term, #r+2# .

Answer: #(6r-5)(r+2)#