Answer:
The number is 7
Step-by-step explanation:
certain positive number: x
x is multipled by 4:
4x
result of this is subtracted from the original number:
so original number minus 4x,
x - 4x
the result is 21 less than 0, this means negative 21
x - 4x = 0 - 21 = -21
do algebra:
-3x = -21
multiply both sides by -1
3x = 21
divide both sides by 3
x=7
(certain positive number: x) is equal to 7
Answer:
51.9 cm²
Step-by-step explanation:
From the diagram attached,
Area of the white region(segment)(A) = Area minor sector- area of the triangle
A = (πr²∅/360°)-(1/2r²sin∅)............... Equation 1
Where r = radius of the circle, Ф = reflex angle formed at the center of the circle, π = pie
From the question,
Given: r = 7 cm, Ф = 150°
Constant: π = 22/7
Substitute these values into equation 1
A = [(22/7)×7²×150/360]-[(1/2)×7²×sin150]
A = 64.17-12.25
A = 51.92
A = 51.9 cm²
A:b=c:d
7.2:x=1:25. If u see two ratios equal each other, the product of a and d is equal to the product of b and c. This means that (7.2 times 25) is equal to x. This equals 180=x. The actual distance of the trail of 180 km. Hope this helps!
Now to solve this problem, all we have to remember is the
formula for calculating the linear speed given the radial speed, that is:
v = r w
where,
v = is the linear velocity or linear speed
r = is the radius of the circular disk = (1 / 2) diameter
= (1/ 2) (2.5 inches) = 1.25 inches
w = is the radial velocity (must be in rad per time) =
7200 rev per minute
Calculating for v:
v = 1.25 inches (7200 rev per minute) (2 π rad / 1 rev)
v = 56,548.67 inches / minute
Converting to miles per hour:
v = 56,548.67 inches / minute (1 mile / 63360 inches) (60
min / hour)
<span>v = 53.55 mile / hour</span>
