If you're working with complex numbers, then I'm sure you're comfortable with plotting them on a complex-plane ... real part of the number along the x-axis, and imaginary part of the number along the y-axis.
When you look at it that way, your two points are simply two points on the x-y plane:
4 - i ===> (4, -1)
-2 + 3i ===> (-2, 3) .
The distance between them is
D = √ (difference in 'x')² + (difference in 'y')²
= √ (6)² + (4)²
= √ (36 + 16)
= √ (52)
= 7.211 (rounded)
3x +2y
A =xy = 6,000,000
y = 6,000, 000/x
L = 2x + 12,000,000/x
3- (12,000,000/x^2) = 0
3 = 12, 000,000/x^2
sqrt x^2 = sqrt 4,000,000
x = 2,000 and y = 3,000 <span>
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The answer to the question