How do you factor 40v^3-62540v3625?

2 Answers
Jun 2, 2015

40=5*840=58
and 625=5*125625=5125
So 40v^3-625=5*(8v^3)+5*(-125)40v3625=5(8v3)+5(125)
40v^3-625=5(8v^3-125)40v3625=5(8v3125)

Jun 2, 2015

40v^3-62540v3625

=5(8v^3-125)=5(8v3125)

=5((2v)^3-5^3)=5((2v)353)

=5((2v)-5)((2v)^2+(2v)5+5^2)=5((2v)5)((2v)2+(2v)5+52)

=5(2v-5)(4v^2+10v+25)=5(2v5)(4v2+10v+25)

...using the difference of cubes identity:

a^3-b^3 = (a-b)(a^2+ab+b^2)a3b3=(ab)(a2+ab+b2)