Question

Mark (✓) against the correct answer:
12x² + 60x + 75 = ?
(a) (2x + 5)(6x + 5)
(b) (3x + 5)²
(c) 3(2x + 5)²
(d) none of these

Answer 1

(c) $3{\left(2x+5\right)}^2$

$$\begin{gathered} 12x^2+60x+75 \\ =3\left(4x^2+20x+25\right) \\ =3\left({\left(2x\right)}^2+2\times 2x\times 5+5^2\right) \\ =3{\left(2x+5\right)}^2 \end{gathered}$$