9514 1404 393
Answer:
after 7 minutes
19,600 feet
Step-by-step explanation:
Here's the "pencil and paper" solution:
The two altitude equations are ...
y = 41300 -3100x
y = 2800x
They can be solved by setting the expressions for y equal to each other.
2800x = 41300 -3100x
5900x = 41300
x = 41300/5900 = 7
y = 2800·7 = 19600
The planes will both be at 19,600 feet after 7 minutes.
We are given with two equations to find the values of two variables, hence the problem can be solved.
Adding the two equations:
x + y = 12<u>x - y = 10
</u>2x = 22
<u />x =11
y = 1
Step-by-step explanation:
We have got the lines :
Both lines intercept the x-axis in the point :
In all point from x-axis the y-component is equal to 0.
We replace the I point in the lines equations:
From the first equation :
From the second equation :
Then 
Finally :
y = ax + b and y = cx + d have the same x-intercept ⇔ad=bc
Solving is :
X=2
Y=1
Step by step
(2x-3) + 5 = 3x
2x+2=3x
X=2
Substitute x by 2
Y=1
