x= a number
sum of= addition
difference= subtraction
is= equal sign
3(5x + 4)= 7(2x - 5)
multiply outer numbers by each term in parentheses
(3 * 5x) + (3 * 4)= (7 * 2x) + (7 * -5)
multiply in parentheses
15x + 12= 14x - 35
subtract 14x from both sides
x + 12= -35
subtract 12 from both sides
x= -47
ANSWER: The number is -47.
Hope this helps! :)