dan ' s age after 20 years will be 7 times his age 4 years ago . what is the present age of dan ?
"let dan ' s present age be x . x + 20 = 7 ( x - 4 ) 6 x = 48 x = 8 the answer is b ."
divide(add(20, multiply(4, 7)), subtract(7, const_1))