Question

The sum of two numbers is 7 and the sum their squares is 23, their product is equal to:​

Answer 1

Answer:

The answer is in the picture

Answer 2

The sum of two numbers is 7 and the sum their squares is 23, their product is equal to:

answer : 13

explanation : Let two numbers are x and y.

a/c to question,

sum of two numbers = 7

or, x + y = 7.....(1)

and sum of their squares = 23

or, x² + y² = 23

• from algebraic identity, a² + b² = (a + b)² - 2ab . similarly, x² + y² = (x + y)² - 2xy.

or, (x + y)² - 2xy = 23

from equation (1),

or, (7)² - 2xy = 23

or, 49 - 2xy = 23

or, 49 - 23 = 2xy

or, xy = 13

hence, product of numbers (i.e., x and y) = 13.

hence, answer is 13.