X = amount of 50% solution
y = total amount after mixing
Note that the amount of alcohol in the 20% solution is 80 (0.2) = 16 oz.
We have 2 unknowns, so we need 2 equations:
first, we can write the equation for the total volume:
y = x + 80
next, apply the percentages to get an equation for the amount of alcohol:
0.4 y = 0.5 x + 16
Finally, solve the pair of equations (in this case, by substitution of the 1st into the second:
0.4 (x + 80) = 0.5x + 16
0.4 x + 32 = 0.5X + 16
rearrange and combine like terms:
0.1x = 16
x = 160
from the 1st equation:
y = 160 + 80 = 240
Answer:
A, B, E, and F
Step-by-step explanation:
sinx and cosx are defined for all values of x. So, sin⁻¹x and cos⁻¹x are also defined for all values of x.
A and E are correct.
tanx is defined for all values of x.
However, tan(nπ) = 0 at when n is an integer. So, tan⁻¹(±nx) is undefined. However, tan⁻¹(-½x) is defined, because -½ is not an integer.
B and F are correct.
C and D are <em>wrong</em>. Both sec⁻¹x and csc⁻¹x are undefined when -1 < x < 1, and -½ is in this forbidden region.
Answer:
Step-by-step explanation:
12/25 =
12 ÷ 25 =
0.48 =
0.48 × 100/100 =
0.48 × 100% =
(0.48 × 100)% =
48%;
Consider the coordinate plane:
1. The origin is the point where Sharon and Jacob started - (0,0).
2. North - positive y-direction, south - negetive y-direction.
3. East - positive x-direction, west - negative x-direction.
Then,
- if Jacob walked 3 m north and then 4 m west, the point where he is now has coordinates (-4,3);
- if Sharon walked 5 m south and 12 m east, the point where she is now has coordinates (12,-5).
The distance between two points with coordinates 
and 
can be calculated using formula
Therefore, the distance between Jacob and Sharon is
