You may express it as :
-18+24x+5x-40=8-20x
49x=56
x=56/49
What do you need help with?
This is the formula for a triangle base
b=2A
hb implement
So 20=2 itmes m2 times 5
5m=5 times m
so
5m=20
5 times m=2 times 2 times 5
divid eboth sides y 5
m=2 times 2
m=4
