Answer:
281 ft^2
Step-by-step explanation:
We need to add each individual 2d shape together to find the surface area
Bottom: 5*12 = 60
Left side and right side: 4*5 = 20, 2 sides so 20*2= 40
Side facing us and side facing away from us: 12*4 = 48, 2 sides so 48*2=96
Top side that is cut by base of triangle: 7*5 = 35
Each triangle face: base = 5 (12-7), height = 5 1/2base * height so each triangle is .5*5*5 = 12.5; 4 triangles so 12.5*4=50
60+40+96+35+50=281
Suppose the length of the card board was x cm by x cm
After squares of 4cm was cut from the corner, the dimension for the box will be:
length=(x-8) cm
width=(x-8) cm
height=4 cm
thus the volume will be:
V=length*width*height
V=4×(x-8)×(x-8)=144
x²-16x+64=36
this can be simplified to form a quadratic equation given by:
x²-16x+28=0
solving the quadratic equation we get:
x=2 or x=14
Thus we conclude that the original dimensions was:
length=14 cm ; width=14 cm
The answer to this question is y = –3x^2, just had this on e2020 :)
Answer:
1) x=1
2) x=6
3) x=3
Step-by-step explanation:
i just did them :) good luck
For simplicity, dy/dx means f'(x);
We have y = ( 8 - x^2 ) / 2x;
Then, y = 4/x - x/2;
So, f'(x) = (4/x - x/2)' = (4/x)' - (x/2)' = -4/(x^2) -1/2 because we use <span> d<span>ifferentiation formulas, such as : (f+g)' = f' + g'; (cf)' = cf'; x'=1; (1/x)' = -1/(x^2);
</span></span>Finally, f'(4) = -4/16 -1/2 = -4/16 - 8/16 = -12/16 = -3/4.
The correct answer is E.
