100,000,000+10,000,000+9,000,000+3
Let x represent the amount of money he invested at 11% and y money he invested at 12%. Now we write system of equations:
x*1.11 + y*1.12 = 70 000 + 7900
x + y = 70 000
We will multiply second equation with 1.11
x*1.11 + y*1.11 = 77700
and subtract if from first:
0.01*y = 200
y = 20000
x = 70000 - 20000 = 50000
Prove:
The angle inscribed in a semicircle is a right angle.
The inscribed angle theorem states that the angle θ, inscribed in a circle is half the measure of the central angle of the circle. So, if the given is a semi-circle, then the inscribed angle is half of 180, therefore, 90 degrees and a right angle. <span />
