6.2.3 Algebraic Expressions (III), PT3 Practice

Posted on February 23, 2018 by user

Question 11:
(a)
Expand: x (2 + y)

(b)

$\begin{array}{l} Express \frac{5}{6 y} - \frac{3 x - 5}{12 y} as a single \\ fraction in its simplest form . \end{array}$

Solution:
(a)
x (2 + y) = 2x + xy

(b)

$\begin{array}{l} \frac{5}{6 y} - \frac{3 x - 5}{12 y} \\ = \frac{5 \times 2}{6 y \times 2} - \frac{3 x - 5}{12 y} \\ = \frac{10 - (3 x - 5)}{12 y} \\ = \frac{10 - 3 x + 5}{12 y} \\ = \frac{15 - 3 x}{12 y} \\ = \frac{3 (5 - x)}{12^{4} y} \\ = \frac{5 - x}{4 y} \end{array}$