How do you factor 72x3228x2+140x?

1 Answer
Feb 18, 2017

72x3228x2+140x=4x(3x7)(6x5)

Explanation:

Complete the square then use the difference of squares identity:

a2b2=(ab)(a+b)

with a=(12x19) and b=9 as follows:

72x3228x2+140x=12x(144x2456x+280)

72x3228x2+140x=12x(144x2456x+36181)

72x3228x2+140x=12x((12x)22(12x)(19)+19281)

72x3228x2+140x=12x((12x19)292)

72x3228x2+140x=12x((12x19)9)((12x19)+9)

72x3228x2+140x=12x(12x28)(12x10)

72x3228x2+140x=12x(4(3x7))(2(6x5))

72x3228x2+140x=4x(3x7)(6x5)