What is the modulus of 2 – 3i?
Answer:
3
Step-by-step explanation:
Easy pythagorean theorum question.
The law states that "A squared plus B squared, equals C squared."
A and B are the two sides that border the 90 degree mark.
C is the hypotenuse or the longest side/diagonal.
Since we know C and A (I chose to use A because why not) we can fill in the equation with what we know
2^2 + ?^2 = 
So
4 + ?^2 = 
Since the 13 is already squared in side of a root, it stays as 13
4 + x^2 = 13
4 - 4 + x^2 = 13 - 4
x^2 = 9
x^2 root = root of 9
x = 3
The missing side is 3.
Or you could use an online calculator xD
(3x-4)(3x-4) is the answer because when something is squared, it's just multiplying itself by itself, this also applies to expressions.
You want y? One way to get y alone would be to mult. all 3 terms by (7/5):
(7/5)(5/7)y = (7/5)*3 - (7/5)(-1/5). This simplifies to:
y = 21/5 * 7/25, or y = 147 / 125.
You could check this using decimal fractions:
y = 4.20 * 0.28 = 1.176 = 147 / 125.
Answer: Choice A. 
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