Factor Completely.?

Work I Did:

3(a^2 - 14a + 49)
3(a - 7)(a - 7)
or
3(a - 7)^2

3 (a² - 14a + 49)
3 (a - 7)(a - 7)
3 (a - 7) ²

First factor out a 3
3(a^2-14a+49)
3(a-7)(a-7)

All the numbers in your problem are divisible by three, so factoring that out gives you:

3 (a^2 - 14a + 49)

Which is recognizable as a square, so factoring that;

3(a - 7)^2

Gives you your answer.

3a^2 - 42a + 147
= 3(a^2 - 14a + 49)
=3(a^2 - 2 * a * 7 + 7^2)
=3 (a - 7)^2; [as, (a^2 - 2ab + b^2) = (a-b)^2]
(ans)

3a^2 - 42a + 147
= 3(a^2 - 14a + 49)
= 3(a - 7)(a - 7)