I only know 23
6x-4 x=4-6=-10
4x+24 x=24-4=20
So! 20-(-10)=10 or 30 because you change the sign with this rule
if the sign are the same you keep change, change. which means keep 20 change - to + and change - to +, so then it becomes 20+(+10)
It would be 12% because .3 divided by 2.5 is .12 which is equivalent to 12%