If the sum of two numbers is 15 and the product is 56, what are the two numbers?
Mathematics · High School · Mon Jan 18 2021
Answered on
Let the first number be x
And, second number be y
Then, according to question
x + y = 15 …1
xy = 56 …2
From equation 1,
y = 15 - x
Putting value of y in equation 2, we ger
x(15-x) = 56
15x - x² = 56
x² - 15x + 56 = 0
Using middle-term split method,
x² - 8x - 7x + 56 = 0
x(x - 8) -7(x -8) = 0
(x -8)(x-7) = 0
x = 8
And, x = 7
Now, value of y when x = 8
8 + y = 15
y = 15 - 8
y = 7
And, value of y when x = 7
7 + y = 15
y = 15 -7
y = 8