Question

1. factorise each of the following expressions

(a) $5x + 20$
$= 5(x + 4)$

(c) $16 - 12x$
$=$
$=$

Explanation:

Step1: Find GCD of 16 and 12

The greatest common divisor (GCD) of 16 and 12 is 4, since \( \text{GCD}(16,12) = 4 \).

Step2: Factor out GCD

Factor out 4 from the expression \( 16 - 12x \). We can write \( 16 = 4\times4 \) and \( 12x = 4\times3x \). So, \( 16 - 12x = 4\times4 - 4\times3x \). Using the distributive property \( ab - ac = a(b - c) \), we get \( 4(4 - 3x) \).

Answer:

\( 4(4 - 3x) \)