To Find :
How many gallons of a 80% antifreeze solution must be mixed with 100 gallons of 20% antifreeze to get a mixture that is 70% antifreeze.
Solution :
Let, x gallons of 80% antifreeze solution is required :
So,

Therefore, 500 gallons of 80% antifreeze solution is required.
Let wind speed = x mph
when she rode 2 miles against the wind we have:-
speed = distance / time so
20 - x = 2 / t -------(1) where t is the time she took.
when riding with the wind we have
20 + x = 3 / t--------(2) adding equations (1) and (2):-
40 = 2/t + 3/t
40 = 5/t
t = 5/40 = 1/8 hr
x = 20 - 2 / 1/8 = 20 - 16 = 4
Wind speed was 4 mph Answer
Use trigonometry here.
sinx = opposite side/ Hypotenuse
so, sinx = 4/5 = 0.8
x= sin^-1(0.8) which is 53.13
Hope it helps
Answer:
try desmos, type in the equation and it shows you the graph
Step-by-step explanation: