Question

Question 20

Fill in the blanks to make each statement true:

9x- ............... =-21 has the solution (-2).

Answer 1

3
Let 9x-m=-21 has the solution (-2).
Since, x=-2 is the solution of the equation.
$\therefore 9\times (-2)-m=-21\Rightarrow -18-m=-21\Rightarrow -18+21=m\Rightarrow m=3$
Hence, 9x-3=-21 has the solution(-2).