Question

if x-y=7andx3-y3=133find xy and x2+y2​

Answer 1

Answer:

xy = -10

x²+y²=29

Step-by-step explanation:

x-y=7

x³-y³=133

xy =?

x2+y2​=?

(x-y)³=x³-y³-3xy(x-y)

7³=133-3xy(7)

343=133-21xy

210= -21xy

xy= -210/21

xy = -10

(x-y)²=x²+y²-2xy

7²=x²+y²-2(-10)

49=x²+y²+20

x²+y²=29