Question

If x - y = 7 and x3 - y3 = 133; find:i) xy
ii) x² + y²
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Answer 1

Here is your answer
Refer to attachment

Answer 2

(x-y)^3=x^3-y^3-3xy(x-y)

(7)^3=133-3xy(7)

343=133-21xy

343-133=-21xy

210=-21xy

210/-21= xy

-10=xy

(x-y)^2=x^2+y^2-2xy

(7)^2= x^2+y^2 -2(-10)

49= x^2+y^2+20

49-20=x^2+y^2

29= x^2+y^2