The correct question is
<span>A student ate 3/20 of all candies and another 1.2 lb. Another student ate 3/5 of the candies and the remaining 0.3 lb. Altogether, what weight of candies did they eat?</span>
let
x-------> total <span>weight of candies
we know that
x=(3/20)*x+1.2+(3/5)*x+0.3
</span>x=(3/20)*x+(3/5)*x+1.5----> multiply by 20----> 20x=3x+12x+30
20x=15x+30
20x-15x=30
5x=30
x=6 lb
the answer is
6 lb
I hope you meant find x
5x + 3x + 2x = 180. x=18
Answer:
Y=2/3 -3
Step-by-step explanation:
Write the left side of the given expression as N/D, where
N = sinA - sin3A + sin5A - sin7A
D = cosA - cos3A - cos5A + cos7A
Therefore we want to show that N/D = cot2A.
We shall use these identities:
sin x - sin y = 2cos((x+y)/2)*sin((x-y)/2)
cos x - cos y = -2sin((x+y)/2)*sin((x-y)2)
N = -(sin7A - sinA) + sin5A - sin3A
= -2cos4A*sin3A + 2cos4A*sinA
= 2cos4A(sinA - sin3A)
= 2cos4A*2cos(2A)sin(-A)
= -4cos4A*cos2A*sinA
D = cos7A + cosA - (cos5A + cos3A)
= 2cos4A*cos3A - 2cos4A*cosA
= 2cos4A(cos3A - cosA)
= 2cos4A*(-2)sin2A*sinA
= -4cos4A*sin2A*sinA
Therefore
N/D = [-4cos4A*cos2A*sinA]/[-4cos4A*sin2A*sinA]
= cos2A/sin2A
= cot2A
This verifies the identity.
Answer:The equation relating I, r, and k is I =K/r²
Step-by-step explanation:
The intensity, I, of a sound varies inversely with the square of the distance, r, from the source of the sound can be written as
I ∝ 1/r²
Introducing the constant of proportionality, K we have that
I =K x 1/r²
Therefore , the equation relating I, r, and k is I =K/r²
