Решение #
The following expressions are used in Ex. 9. though the wordings of some of them may vary a little.
to solve the equation
to multiply something by something
to find out the value of the unknown variable X
to get the result
to simplify the mathematical expression
to transfer the unknown variables to the left-hand side
to express variable Y through the variable X
to apply the formula for the equation
to take out of the brackets