Answer:
D: 8,100π in²
Step-by-step explanation:
The formula for area of a circle is
A = πr²
The radius is squared, so if the radius or a new circle is 6 times larger (multiplied by 6), the difference in area will be 36 times greater. So the area is
225π(36) = 8,100π
Answer:
-1 < c < 9
Step-by-step explanation:
-6<2c-4<14
Add 4 to all sides
-6+4<2c-4+4<14+4
-2<2c<18
Divide by 2
-2/2<2c/2<18/2
-1 < c < 9
Answer:
D. Minimum at (3, 7)
Step-by-step explanation:
We can add and subtract the square of half the x-coefficient:
y = x^2 -6x +(-6/2)^2 +16 -(-6/2)^2
y = (x -3)^2 +7 . . . . . simplify to vertex form
Comparing this to the vertex for for vertex (h, k) ...
y = (x -h)^2 +k
We find the vertex to be ...
(3, 7) . . . . vertex
The coefficient of x^2 is positive (+1), so the parabola opens upward and the vertex is a minimum.
x/110 = (320-x)/90
<span> Cross multiply</span>
90x = 35200-110x
200x=35200
X = 35200/200 = 176 (distance traveled by train going 110 mph
176/110 = 1.6 hours = 1 hour and 36 minutes
Check: 110*1.6 = 176, 90*1.6 = 144
176+144 = 320
it will take 1.6 hours ( 1 hour 36 minutes) for the trains to meet
For this case we have the following variables:
x = the number of drill-based workouts
y = the number of conditioning workouts
The system of equations that adapts to the situation is:
"According to her schedule, she can complete at most 10 workouts this week":
x + y <= 10
"It takes Gianna 45 minutes to complete her drill-based workouts and 30 minutes to complete her conditioning workouts. She is required to spend more than 450 minutes on workouts every week"
45x + 30y> 450
Answer:
A system of inequalities can that be used is:
x + y <= 10
45x + 30y> 450