*six less than the quotient of d and g
The quotient of d and g is d/g. Six less than this is d/g - 6.
*ten less than twice the product of s and t
The product of s and t is st, twice this is 2st. Ten less than the expression is 2st - 10.
*four more than the product of x and y
The product of x and y is xy. Four more than this is is xy + 4.