Question

the sum of 7 numbers. is 133. If one more is added, the mean of the numbers are 20. Find the added number. Question

Answer 1

Answer:

Given x +y= 7

X cube+ycube=133

We know (x+y)^3=x^3+y^3+3xy(x+y)

Substituting the given, equation becomes

7^3=133+3xy(7)

343=133+21xy

Hence xy=10

We know (x+y)^2=x^2+y^2+2xy

Substitute values of x+y and xy

7^2=x^2+y^2+20

49–20= x^2+y^2

Hence sum of their squares is 29

Answer 2

Answer:

Step-by-step explanation: Answer is 27