P = 18,000
R=6%
T=7 years
A = P ( 1 + 1 divided by r) raised to n
Substitute the numbers an u will fin the answer
Answer:
m + n = 15
m - 3 = n
The numbers are 9 and 6
Step-by-step explanation:
From the question,
The sum of two numbers is fifteen; the first number is m and the second number is n. To translate to a system of equations, we can write that
m + n = 15 ..... (1)
Also, from the question,
One number is three less than the other,
Also, to translate to a system of equations, we can write that
m - 3 = n ...... (2)
If desired, we can determine m and n
From equation (1)
m + n = 15
Then,
m = 15 - n ...... (3)
Put the value of m in equation (3) into equation (2)
m - 3 = n
Then
15 - n - 3 = n
15 - 3 = n + n
12 = 2n
n = 12/2
∴ n = 6
For m, put the value of n into equation 3
m = 15 - n
m = 15 - 6
m = 9
∴ m = 9 and n = 6
Hence, the numbers are 9 and 6
let the speed of plane in still air be x and that wind be y
therefore:
x+y=490
x-y=390
next we solve for the values of x and y, first we add the above equations. This will give us:
2x=880
x=880/2
x=440 miles per hour.
substituting the value of x in one of the equations and solving for y we get:
440+y=490
y=490-440
y=50 miles per hour
