Question

What is the value of the unknown in the following equations? [4 MARKS]

(i) $2x+4=10$

(ii) $11x-7=5(x+7)$

(iii) $7m+\frac{19}{2}=13$

(iv) $2y+\frac{5}{2}=\frac{37}{2}$

Answer 1

Each part: 1 Mark each

(i) $2x+4=10$

$\Rightarrow 2x=10-4$

$\Rightarrow 2x=6$

$\Rightarrow x=\frac{6}{2}=3$


(ii) $11x-7=5(x+7)$

$\Rightarrow 11x-7=5x+35$

$\Rightarrow 11x-5x=35+7$

$\Rightarrow 6x=42$

$\Rightarrow x=\frac{42}{6}=7$


(iii) $7m+\frac{19}{2}=13$

$7m=13-\frac{19}{2}$

$7m=\frac{26-19}{2}$

$7m=\frac{7}{2}$

$m=\frac{7}{2\times 7}$

$m=\frac{1}{2}$


(iv) $2y+\frac{5}{2}=\frac{37}{2}$

$2y=\frac{37}{2}-\frac{5}{2}$

$2y=\frac{37-5}{2}$

$2y=\frac{32}{2}$

$y=\frac{32}{4}$

$y=8$