SOLUTION: The value of x^2+y^2 when x+y=5 and xy=3 is A) 18 B) 19 C) 20 D) 21

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: The value of x^2+y^2 when x+y=5 and xy=3 is A) 18 B) 19 C) 20 D) 21      Log On


   

Question 1132296: The value of x^2+y^2 when x+y=5 and xy=3 is
A) 18
B) 19
C) 20
D) 21
Found 2 solutions by Alan3354, ikleyn:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The value of x^2+y^2 when x+y=5 and xy=3
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x+y=5
x^2 + 2xy + y^2 = 25
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2xy = 6
x^2 + y^2 = 19

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
x%5E2 + y%5E2 = %28x%2By%29%5E2+-+2xy = 5%5E2+-+2%2A3 = 25 - 6 = 19.     ANSWER


Option B).