1) let both have x ,
so putting in eqn ;
4x+0.50 = 9x-3
5x=2.50
x=0.50
therefore both have 50 p in the beginning !!
2) let the number be x
so in eqn;
(x+18)/2=5x
x+18=10x
9x=18
x=2
so the number must be 2 !!
if you have still any problem, comment !!
7/8 equals 0.875
80% equals 0.8
Which means that 7/8 is greater than 80%
A perpendicular bisector literally bisect the perpendicular intersection in half the angle bisector is half of the angle. for example a 90 degree angle split in half is 45 degrees on both sides
the answer for your question is, A+7