38 words because for every week he practices his words per minute increase by 4
Answer:
x = -2 ±sqrt(7)
Step-by-step explanation:
3x^2 +12 x = 9
Divide each side by 3
3x^2 /3 +12x/3 = 9/3
x^2 +4x = 3
Take the coefficient of x
4
Divide by 2
4/2 =2
Square it
2^2 =4
Add it to each side
x^2 +4x+4 = 3+4
x^2 +4x+4 = 7
(x+2)^2 = 7
Take the square root of each side
x+2 = ±sqrt(7)
Subtract 2 from each side
x+2-2 = -2 ±sqrt(7)
x = -2 ±sqrt(7)
Answer:
49.
7×7=49.
Step-by-step explanation:
i did this. hope it helps
Answer:
Step-by-step explanation:
The formula to calculate the surface area of a sphere is the following:
Where A is the area of the sphere and r is the radius of the sphere.
In this case we know that the diameter d of the sphere is:
The diameter is:
.
Thus
Then the surface area of the sphere is:
Answer:
Length of the room is 180 ft
Step-by-step explanation:
We have a rectangular room with dimensions:
width = 70 ft and length "x" (unknown)
Perimeter of a rectangle is 2*w + 2*x and according to problem statement 500 ft of lights will fit exactly in room perimeter then:
2*70 + 2*x = 500
140 + 2*x = 500
2*x = 500 - 140
2*x = 360
x = 360/2
x = 180 ft
