How do you factor $25a ^ { 2} - 45a + 18$ ?

Question

1542 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-05-13T05:01:47

$(5x-6)(5x-3)$

$25a^2-45a+18$ = $25x^2-45x+18$ which is in the general form $ax^2+bx+c$
(i changed the a to x so that the general form would work)

You can either use the "cross" method or the quadratic formula.

So for the quadratic formula which is

$x=(-b+-sqrt(b^2-4ac))/(2a)$

$x=(45+-sqrt(45^2-4*25*18))/(2*25)$

$x=(45+-sqrt(225))/50$

$x=(45+-15)/50$

$x=(45+15)/50$ or $x=(45-15)/50$

$x=60/50$ or $x=30/50$

$x=6/5$ or $x=3/5$

$25x^2-45x+18 = (x-6/5)(x-3/5) = (5x-6)(5x-3)$

How do you factor 25a ^ { 2} - 45a + 1825a ^ { 2} - 45a + 18?