Question

Square root of the expression $16a^2+9b^2-24ab+24a-18b+9$ is .

• A. $|4a-3b+3|$
• B. $|4a+3b+3|$
• C. $|4a-3b-3|$
• D. $|4a+3b-3|$

Answer 1

The correct option is A $|4a-3b+3|$

$\sqrt{16a^2+9b^2-24ab+24a-18b+9}$
= $\sqrt{(4a{)}^2+(3b{)}^2+(3{)}^2+2(4a\left)\right(-3b)+2(-3b\left)\right(3)+2(4b\left)\right(3)}$
= $\sqrt{(4a-3b+3{)}^2}$
= $|4a-3b+3|$