How do you factor #12s x - 21t x + 28s y ^ { 2} - 49t y ^ { 2}# by grouping?

Question

440 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-03-25T13:53:41

See the entire solution process below:

First, rewrite this expression as:

#(12sx - 21tx) + (28sy^2 - 49ty^2)#

Next, out of the left term factor out a #3x# and out of the right term factor out a #7y^2#:

#((3x * 4s) - (3x * 7t)) + ((7y^2 * 4s) - (7y^2 * 7t))#

#3x(4s - 7t) + 7y^2(4s - 7t)#

Now, factor out a #(4s - 7t)# from each term:

#(4s - 7t)(3x + 7y^2)#