Question

Match the following algebraic equation with it's solution.

• A. $5$
• B. $30$
• C. $2$
• D. $16$

Answer 1

Let's look at the equations one by one and solve them:

A. $3x+5=20$
$\Rightarrow 3x=20-5=15$
$\Rightarrow 3x=15$
$\Rightarrow x=\frac{15}{3}=5$

B. $\frac{x}{2}+10=25$

$\Rightarrow \frac{x}{2}=25-10=15$

$\Rightarrow \frac{x}{2}=15$

$\Rightarrow x=2\times 15=30$

C. $9a+\frac{a}{2}=19$

We can add the terms "$9a$" and "$\frac{a}{2}$" as the unknown are the same.

$\Rightarrow 9a+\frac{a}{2}=\frac{9a\times 2+a}{2}=19$

$\Rightarrow \frac{19a}{2}=19$

Cancelling $19$ from both sides:

$\frac{a}{2}=\frac{19}{19}=1$

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

$a=2$

D. $\frac{z+5}{3}+1=8$

$\Rightarrow \frac{z+5}{3}=8-1=7$

$\Rightarrow \frac{z+5}{3}=7$

$\Rightarrow z+5=7\times 3=21$

$\Rightarrow z+5=21\Rightarrow z=16$