Answer: The required value of the given expression is 30.
Step-by-step explanation: We are given that
\(4x-3y=10~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)\)
We are to find the value of the following expression :
\(12x-9y.\)
We have
\(12x-9y\\\\=3(4x-3y)\\\\=3\times10~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~[\textup{Using equation (i)}]\\\\=30.\)
Thus, the required value of the given expression is 30.
