There are two ways to work this out: normal variables or using "imaginary" numbers.
Normal variables:
![(7+2i)(3-i)\\(7*3)+[7*(-i)]+(3*2i)+[2i*(-i)]\\21-7i+6i-2i^{2}\\\\21-i-2i^{2}](https://tex.z-dn.net/?f=%20%287%2B2i%29%283-i%29%5C%5C%287%2A3%29%2B%5B7%2A%28-i%29%5D%2B%283%2A2i%29%2B%5B2i%2A%28-i%29%5D%5C%5C21-7i%2B6i-2i%5E%7B2%7D%5C%5C%5C%5C21-i-2i%5E%7B2%7D)
Imaginary numbers:
Using the result from earlier:
Now since
, then the expression becomes:
Answer: B: 20
Step-by-step explanation: We can take 40% as a fraction to make it 4/10, simplifying gives 2/5. 2/5 of 50 is 20!
Hope this Helps!
Answer:
6.25 pi cm^2
Step-by-step explanation:
The formula for circumference is
C = 2*pi*r
We know the circumference is 5 pi
5 pi = 2 * pi *r
Divide each side by pi
5 pi/pi = 2 * pi *r/pi
5 = 2r
Divide by 2
5/2 = 2r/2
2.5 = r
We need to find the area of the circle
The area is given by
A = pi * r^2
= pi * (2/5)^2
= pi *6.25
= 6.25 pi cm^2
When system of equations solved graphically, the solutions are points of interceptions, So here, the solution is the point of interception (0,-5).
Answer (0,-5).
