Answer:
60°
Step-by-step explanation:
they are equal.....
It's 21 square units. If you map it on a complex plane (x-axis is real numbers, y-axis is imaginary numbers) you'll see that the sides of the rectangle is 3 and 7 which multiply to 21.
A polynomial that has these factors could be

.
Okay, so:
You would want to find what 1/10 of the laptop costs. That would be the 10% of money left in Kai's account.
So,
423*.1
(you have to turn the percentage into a decimal; 10%= .10
423*.1= 42.3
So, Kai has 42.3 dollars left to buy a scanner. He only has 10% of his bank account left to spend on the scanner.
I hope this helps!
~cupcake