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:
Length 34 cm
Width 8 cm
Step-by-step explanation:
Let
x-----> the length of the rectangle
y----> the width of the rectangle
we know that
The perimeter of rectangle is equal to
P=2(x+y)
P=84 cm
so
84=2(x+y)
42=x+y ----> equation A
x=4y+2 -----> equation B
substitute equation B in equation A and solve for y
42=(4y+2)+y
5y=42-2
y=40/5=8 cm
Find the value of x
x=4y+2 ----> x=4(8)+2=34 cm
The dimensions are
Length 34 cm
Width 8 cm
Answer: i would say 60 cm sorry if im wrong i think your missing a number
Step-by-step explanation:
Answer:
The answer is 6!
Step-by-step explanation:
