Question

if X square + Y square equals to 49 and x minus y equals to 3 then find the value of x cube minus y cube ​

Answer 1

Step-by-step explanation:

x² + y² = 49

x - y = 3

than,

x³ - y³ = ?

so,

x³ - y³ = ( x - y ) ( x² + y² + xy)

= 3 ( 49 + xy )

= 147 + 3xy

Answer 2

Answer:

407      or   657

Step-by-step explanation:

x²+y²=49

x-y=3

x=3+y

∴(3+y)²+y²=49

∴9+6y+y²=49

∴y²+6y=40

∴y²+6y-40=0

∴y²+10y-4y-40=0

∴y(y+10)-4(y+10)=0

∴(y-4)(y+10)=0

∴y-4=0 or y+10=0

∴y=4 or y=-10

∴x=3+y

∴x=3+4=7

or x=3-10=-7

∴ x³-y³=7³-4³ or     -7³-(-10)³

=343+64   or    -343+1000

=407      or   657