Answer:
D
Step-by-step explanation:
(a+4)(a-2)=a^2+2a-8
a*a=a^2
a*(-2)=-2a
a*4=4a
4*(-2)=-8
a^2-2a+4a-8=a^2+2a-8
Answer:
5/ sqrt2
Step-by-step explanation:
A=b.a.SinC
Answer:
200π
Step-by-step explanation:
Surface area of a cone = πr(r+l)
r is the radius
l is the slant height
Volume of the cone = 1/3πr²h
320π = 1/3πr²h
320 = 1/3r²(15)
320 = 5r²
r² = 320/5
r² = 64
r = 8
l² = 15² + 8²
l² = 225 + 64
l² = 289
l = 17
Get the surface area;
S = πr(r+l)
S = π8(8+17)
S = π*8*25
S = 200π
Hence the surface area of the cone is 200π
Answer:
10 years
Step-by-step explanation:
let they become of same height after t years
3ft=36 inches
hence
height of A
Ha=36+21t
8ft=96 inches
height of B
Hb = 96+15t
as Ha =Hb
36+21t =96+15t
21t-15t =96-36
6t=60
t=60/6
t= 10 years
