Answer: a =3c-15b
b = c/5-a/15
Step-by-step explanation:
-2a-9=6a+15
Move 6a to the other side. Sign changs from +6a to -6a.
-2a-6a-9=6a-6a+15
-2a-6a-9=15
-8a-9=15
Move -9 to the other side. Sign changes from -9 to +9.
-8a-9+9=15+9
-8a=15+9
-8a=24
Divide both sides by -8
-8a/-8=24/-8
a=-3
Answer: a=-3
Answer:
1287
Step-by-step explanation:
Number of people in elevator , n = 8
Number of floors, r = 6
Since they all look alike, arrangement doesn't matter, the we use combination :
(n+r-1 r - 1) = (8+6-1 C 6-1) = 13C5
Recall:
nCr = n! / (n-r)!r!
13C5 = 13! / (13-5)!5!
13C5 = 13*12*11*10*9 / 5*4*3*2*1
= 1287
Answer:
The volume of the pyramid is 
Step-by-step explanation:
we know that
The volume of the pyramid is equal to

where
B is the area of the base of the pyramid
H is the height of the pyramid
we have


substitute

Answer:
- Circumference = 69.14cm
- Area = 380.29cm²
Step-by-step explanation:
Circumference.
Circumference of a circle is calculated by the formula:
= Pie * diameter
= π * diameter
= 22/7 * 22
= 69.14 cm
Area
Area of circle:
= Pie * radius ²
Radius = diameter/2
= 22/2
= 11 cm
Area = 22/7 * 11²
= 22/7 * 121
= 380.29 cm²