Question

factorize this expression completely
using (a-b)² formula
3a²- 36a + 108​

Answer 1

Answer:

$3a^2 - 36a + 108 = (\sqrt{3}a - 6\sqrt{3} )^2$

Step-by-step explanation:

$3a^2 = (\sqrt{3} a)^2\\108 = 9 \times 4 \times 3= 3^2 \times 2^2 \times 3 = (3\times2 \sqrt{3} )^2 = (6\sqrt{3})^2$

$so, a = \sqrt{3} a \ , \ b = 6\sqrt{3} \\\\(a - b)^2 = a^2 -2ab + b^2\\\\-36a = -2ab\\\\-36a = -2 \times \sqrt{3} a \times 6\sqrt{3}$

Therefore ,

$3a^2 - 36a + 108 = (\sqrt{3}a )^2 - 2(\sqrt{3}a \times 6\sqrt{3} ) + (6\sqrt{3} )^2 = (\sqrt{3}a - 6\sqrt{3} )^2$