Question

If $\frac{\left(1.2\right)(0.5x+0.4)}{2}=0.6$, then $x=$

• A. $1.3$
• B. $1.2$
• C. $1.1$

Answer 1

The correct option is B $1.2$

$\frac{\left(1.2\right)(0.5x+0.4)}{2}=0.6$

On multiplying the RHS and LHS of the equation by '2', we get,

$\Rightarrow \frac{\left(1.2\right)(0.5x+0.4)}{2}\times 2=0.6\times 2$

$\Rightarrow \left(1.2\right)(0.5x+0.4)=1.2$

Now, on dividing both sides of the equation by '$1.2$', we get,

$\Rightarrow \frac{\left(1.2\right)(0.5x+0.4)}{1.2}=\frac{1.2}{1.2}$

$\Rightarrow 0.5x+0.4=1$

On multiplying both sides of the equation by '$10$', we get,
$\Rightarrow (0.5x+0.4)\times 10=1\times 10$
$\Rightarrow 5x+4=10$

On subtracting '4' from both sides of the equation, we get,
$\Rightarrow 5x+4-4=10-4$
$\Rightarrow 5x=6$

On dividing both sides of the equation by '5', we get,
$\Rightarrow \frac{5x}{5}=\frac{6}{5}$

$\Rightarrow x=\frac{6}{5}=\frac{6\times 2}{5\times 2}$

$\Rightarrow x=\frac{6}{5}=\frac{12}{10}=1.2$

$x=1.2$ is the required value