SOLUTION: 3+sqrt-25 divided by 4-sqrt-64

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Question 70652: 3+sqrt-25 divided by 4-sqrt-64
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
3+sqrt-25 divided by 4-sqrt-64
:
%283%2Bsqrt%28-25%29%29%2F%284-sqrt%28-64%29%29
:
%283%2Bsqrt%2825%2A-1%29%29%2F%284-sqrt%2864%2A-1%29%29
When have a sqrt of a negative, you must use "i" which is defined as the Sqrt(-1)
Find the square roots of 25 and 64 and -1 and you have:
:
%283+%2B+5i%29%2F%284+-+8i%29
:
They generally do not want "i" in the denominator so we multiply (4 - 8i) by it's
conjugate which is (4 + 8i); any number over itself is 1 so:
:
%283+%2B+5i%29%2F%284+-+8i%29 = %284+%2B+8i%29%2F%284+%2B+8i%29 = %2812+%2B+24i+%2B+20i+%2B+40i%5E2%29%2F+%2816+%2B+32i+-+32i+%2B+64i%5E2%29 = %2812+%2B+44i+%2B+40%28-1%29%29%2F+%2816+-+64%28-1%29%29 = %2812+%2B+44i+-+40%29%2F%2816+%2B+64%29%29 = %28-28+%2B+44i%29%2F80
We can reduce the fraction (divide by 4) to %28-7+%2B+11i%29%2F20