Firstly, the rate of increase of Canton = 80/7720 = 0.010
The rate of increase of HP = 120/3200 = 0.0375
Apply the formula of compound interest==> A =A'(1+i)^n
The population will be equal when the following equality is satisfied
7720(1+0.01)^n = 3200(1+0.0375)^n
or
7720x1.01^n = 3200x1.0375^n
Divide both sides by 3200 ===>(193/80)x1.01^n=1.0375^n
Rhombus -> 2 equivalent obtuse angles, 2 equivalent acute angles
vs.
Rectangle -> 4 equivalent right angles.
Let the first number be x and decide number be y
therefore x+y = -42
also. x-y = 52 using the process of elimination
we get: 2x = 10
we divide both sides by 2, which gives us x=5
then we substitute the value of x in the first equation
that gives us. 5+y = -42
thus. y = -47
I'm guessing 99.65
1800+10%-20%-25%=99.65
but it probably wrong