Question

Put the correct number in the box, so that the equation remains true.

If $\text{10a=55-a}$ then $\boxed{}\times 10\mathrm{a}=8(55-\mathrm{a})$

Answer 1

Given, $\text{10a=55-a}$

$\text{⇒10a=55-a}$

Multiply both sides by $8$ we get:

$$\begin{gathered} \text{⇒10a×8=}\left(\mathrm{55-}a\right)\text{×8} \\ \Rightarrow 8\times 10a=8\left(\mathrm{55-}a\right)[\mathrm{By}\mathrm{assocoiative}\mathrm{property}] \end{gathered}$$

By comparing it with $\boxed{}\times 10\mathrm{a}=8(55-\mathrm{a})$
We get $8$ as the number to be filled in the box.

Hence, If $\text{10a=55-a}$ then $\boxed{8}\times 10\mathrm{a}=8(55-\mathrm{a})$.