7+ (-5) = 2.
Therefor, 4^2 would be the right answer.
Let a = speed of the plane A, and b = speed of plane B.
(Assume that the net effect of the wind is negligible.)
From the first sentence, the distance between A and B after each travels for 1 hour is a + b miles. From the second sentence, after 45 minutes, or 0.75 hour, the distance between A and B is 200 miles. Plane a has traveled 0.75a, while plane B has traveled 0.75b.
Hence a + b = 0.75a + 0.75b +200
==> 0.25(a + b) = 200.
==> a + b = 800.
Therefore planes A and B are 800 miles apart now.
When there's more than one letter, and you just have to solve for one variable, you can just solve it like you would any other equation. Treat the other variables like numbers and add, subtract, multiply, and divide them to both sides of the equation in order to isolate the variable you want to solve for.
Answer: 12.5 cm
Step-by-step explanation:
Equation would be:
1:80
?:1000
So you'll just have the cross multiply the equation above to find ? ( scale drawing lake). It'll be 1000*1/80 which will be 12.5 cm.
What is the model. Because I cannot do anything without a model...