Step-by-step explanation:
(a-b)^2=a^2-2ab+b^2
X^2-2(X)(5)+5^2
Ans C
X^2-10X+25
Answer:
DA/dt = 75.27 cm²
Step-by-step explanation:
Cube Volume = V(c) = 683 cm³
DV(c) /dt = 824 cm³
V(c,x) = x³
Then
DV(c,x)/ dt = 3x² Dx/dt
( DV(c,x)/ dt )/ 3x² = Dx/dt (1)
Now as V(c,x) = x³ when V(c,x) = 683 cm³ x = ∛683
x = 8.806 ( from excel)
And by subtitution of this value in equation (1)
Dx/dt = ( DV(c,x)/ dt )/ 3x² ⇒ Dx/dt = 824 / 3*x²
Dx/dt = 824 /3*77.55
Dx/dt = 824/232,64
Dx/dt = 3,542
Then we got Dx/dt where x is cube edge. The area of the face is x² then
the rate of change of the suface area is
DA/dt = ( Dx/dt )²*6 ( 6 faces of a cube)
DA/dt = (3.542)²*6
DA/dt = 75.27 cm²
Area of trapezoid = Average length of parallel lines x height
3+22=25
25/2= 12.5
12.5x6=75cm^2
Answer:
(8,21)
Step-by-step explanation:
Since both equations equal y, set both equaitions equal to each other
and solve for x
4x-11=x+13 , subtract x from both sides
3x-11=13, add eleven to both sides
3x=24, divide both sides by 3 to get x alone
x=8
Substitute x=8 into either equation to solve for y
y=4(8)-11
y=32-11
y=21
