Question

x+y=1 and x-y=7 find
5(x²+y²) and xy
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Answer 1

Answer:

Basically it is just dependent on the identity that is (x+y)²=x²+y²+2xy

As x+y= 5 and xy=7, we just have to put given values in identity

(5)²=x²+y²+2(7)

25=x²+y²+14

x²+y²=25–14

x²+y²=11.

Here is your final answer.

Thankyou.