Answer:
D. C = 0.59x+ 275
Step-by-step explanation:
Answer:
the first option is correct
since value of a will be found through division.
One number is 4 times the other, so x and 4x.
The sum of two numbers is 4x+x=70.
Solve for x to get
x=70/5=14
the other number is 4x=4*14=56
Let
x------> the length side of the square base of the box
y-------> the height of the box
we know that
volume of the box=b²*h
b=x
h=y
volume=256 cm³
so
256=x²*y------>y=256/x²--------> equation 1
<span>The amount of material used is directly proportional to the surface area, so we will minimize the amount of material by minimizing the surface area.</span>
surface area of the cardboard=area of the base+perimeter of base*height
area of the base=x²
perimeter of the base=4*x
height=y
surface area=x²+4x*y-----> equation 2
substitute equation 1 in equation 2
SA=x²+4x*[256/x²]-----> SA=x²+1024/x
step 1
find the first derivative of SA and equate to zero
2x+1024*(-1)/x²=0------> 2x=1024/x²----> x³=512--------> x=8 cm
y=256/x²------> y=256/8²-----> y=4 cm
the answer is
the length side of the square base of the box is 8 cm
the height of the box is 4 cm
Length of the side = 9 cm
Diagonal = 
cm
Solution:
Area of the square = 81 square centimeters
In square all sides are equal.
Area of the square = side × side
Side × side = 81
Side² = 9² (∵81 = 9²)
Taking square root on both sides, we get
Side = 9 cm
Length of the side = 9 cm
To find the length of the diagonal:
In square all the angles are right angle.
Diagonal splits the square into two right angle triangle.
Using Pythagoras theorem,
<em>In right triangle, square of the hypotenuse is equal to the sum of the square of the other two sides.</em>
Here, diagonal is the hypotenuse.
Taking square root on both side,
Diagonal = cm
