248 , 842....aquí están los números....
The first question is 50% because a total of 30 girls bought lunches out of 60 kids
the second question, the easiest way is to plug in the x and y coordinates
3(4) - 2(0) = 12
12-0=12
12=12
because 12 = 12 is true, the first pair is the answer
Answer:
3.5
Step-by-step explanation:
in order to find the maximum, we are basically solving to find the vertex of the graph. to find the vertex use :
-b/2a
the 'b' is 112
the 'a' is -16
so :
-112/-32 = 3.5
Maybe take a picture of it?
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
