Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
7*x-4-(21)=0
Solve : 7x-25 = 0
Add 25 to both sides of the equation :
7x = 25
Divide both sides of the equation by 7:
x = 25/7 = 3.571
4x^2-3x and I have to have 20 characters
-45x+72
you multiply the 9 by everything in the parentheses
