The sum of two decimal numbers is 3.9
Their difference is 0.9,and their product is 3.6
What are the two numbers?
x+y = 3.9
x-y = .9
add them
2x = 4.8
x = 2.4
then y = 3.9-2.4 = 1.5
check:
what is the product?
2.4(1.5) = 3.6
BTW, the last bit of information was not necessary.
3.9
5.13
5.13
To find the two decimal numbers, let's assign variables to each number. Let's call the first number x and the second number y.
From the given information, we have the following equations:
Equation 1: x + y = 3.9 (sum of the two numbers is 3.9)
Equation 2: x - y = 0.9 (difference of the two numbers is 0.9)
Equation 3: x * y = 3.6 (product of the two numbers is 3.6)
Now we have a system of three equations with two variables.
To solve this system, we can use the method of substitution or elimination. Let's solve it using the method of substitution:
From Equation 2, we have:
x = y + 0.9
Substitute this value of x in Equation 1:
(y + 0.9) + y = 3.9
2y + 0.9 = 3.9
2y = 3.9 - 0.9
2y = 3
Divide both sides by 2:
y = 3 / 2
y = 1.5
Now substitute this value of y in Equation 2:
x - 1.5 = 0.9
x = 0.9 + 1.5
x = 2.4
Therefore, the two numbers are x = 2.4 and y = 1.5.