We need to write the expression 3(x + y) = 2y - x in a verbal sentence. We do as follows:
Three times the sum of x and y is equal to two times y minus x.
or
The sum of x and y multiplied by three is equal to the difference of two y and x.
or
Three quantity x plus y is equal to the product of two and y minus x.
or
Three multiplied by the sum of x and y is equal to two times y minus x.
Either of the statements I have written above would be correct and would mean the same equation.