Answer:
x=1, y=-5
Step-by-step explanation:
Given equations are:

In order to solve the equation
Multiplying Eqn 1 by 5 and eqn 2 by 3 and subtracting them
So,
Eqn 1 becomes
15x+50y=-235
Eqn 2 becomes
15x-21y=120
Subtracting 2 from a
15x+50y - (15x-21y) = -235-120
15x+50y-15x + 21y = -355
71y = -355
y = -355/71
y =-5
Putting y= -5 in eqn 1
3x+10(-5) = -47
3x -50 = -47
3x = -47+50
3x = 3
x = 3/3
x = 1
Hence the solution is:
x=1, y=-5
Answer:
257.5 mph
332.5 mph
Step-by-step explanation:
The initial distance between the two planes is 960 miles, while the final distance (after t=1.5 h) is 75 miles, so the total distance covered by the two planes in 1.5h is
miles
Calling v1 and v2 the velocities of the two planes, we have the following equations:
(1)
--> velocity of plane 1 exceeds velocity of plane 2 by 75 mph
(2)
--> the total distance covered by the two planes is 885 miles (t=1.5 h is the time, and the products v1 t and v2 t represent the distance covered by each plane)
Substituting t=1.5 h, the second equation becomes:

By substituting (1) into this last equation, we find:

And substituting this back into eq.(1), we find

So, the speeds of the two planes are
257.5 mph
332.5 mph
Answer:
Step-by-step explanation:
We are given the following in the question:
Population mean, μ = 108
Sample mean,
= 107
Sample size, n = 110
Alpha, α = 0.02
Population standard deviation, σ = 7
Formula:
Putting all the values, we have

The test statistic is -1.50
1. You can subtract everything with the same “value” so that means you can subtract 3x from 6x, 5y - 5y and 39 - 27. This will give you: 3x + 0 = 12. Because 0 isn’t anything you get 3x = 12. Dividing everything by 3 you get x = 4