Factor completely 4a² -15a +9?

Hi,

4a² -15a +9 = (a - 3)(4a - 3)

I hope that helps!! :-)

(4a - 3)(a - 3)

4a² - 15a + 9

Find two numbers that add up to -15 and multiply to 4*9 = 36. -12 and -3 are the two numbers.

Use the method of factor by grouping:

4a² - 12a - 3a + 9

4a(a - 3) - 3(a - 3)

(4a - 3)(a - 3)

4a^2 - 15a + 9 = (4a - 3)(a - 3)

(a-3) (4a-3)

4a² - 15a + 9 = (4a - 3)(a - 3)

4a² - 15a + 9

(4a-3)(a-3)

4a^2 - 15a + 9
= 4a^2 - 12a - 3a + 9
= 4a(a - 3) - 3(a - 3)
= (4a - 3)(a - 3)