Answer:
- 6 2/3 qt 80%
- 13 1/3 qt 20%
Step-by-step explanation:
It is often convenient to solve a mixture problem by letting a variable represent the quantity of the higher-concentration contributor to the mix.
__
We can let x represent the number of quarts of 80% solution needed. Then (20-x) is the number of quarts of 20% solution needed. The amount of salt in the final mix is ...
0.80x +0.20(20-x) = 0.40(20)
0.60x = 0.20(20) . . . . . . . . subtract 0.20(20) and simplify
x = 20/3 = 6 2/3 . . . . . . . . . divide by 0.60; quarts of 80% solution
(20 -x) = 13 1/3 . . . . . . . . . . amount of 20% solution needed
The teacher should mix 6 2/3 quarts of 80% solution with 13 1/3 quarts of 20% solution.
Answer:
+120/169 or -120/169
Step-by-step explanation:
- let
![cos^{-1}[\frac{5}{13} ] = \alpha](https://tex.z-dn.net/?f=cos%5E%7B-1%7D%5B%5Cfrac%7B5%7D%7B13%7D%20%20%5D%20%3D%20%5Calpha)
where, alpha is some angle that satisfies the assumed condition.
- so,
[ taking cos to the other side or applying cos on both sides]
- now, substitute this in the given expression
as sin
= 
[by general trigonometry formula: ![cos^{2}[\beta] +sin^{2}[\beta]=1](https://tex.z-dn.net/?f=cos%5E%7B2%7D%5B%5Cbeta%5D%20%20%2Bsin%5E%7B2%7D%5B%5Cbeta%5D%3D1)
]
so if , we can get sin
from the above formula as + or - 12/13
(because, after taking square root on both sides we keep + or -]
- as, sin
![2\beta = 2*sin[\beta ]*cos[\beta ]](https://tex.z-dn.net/?f=2%5Cbeta%20%20%3D%202%2Asin%5B%5Cbeta%20%5D%2Acos%5B%5Cbeta%20%5D)
[by general trigonometry formula]
- here, now
![sin[2\alpha ]=2*(+or- 12/13)*5/13\\](https://tex.z-dn.net/?f=sin%5B2%5Calpha%20%5D%3D2%2A%28%2Bor-%2012%2F13%29%2A5%2F13%5C%5C)
so, the final value can be 120/169 or -120/169.
3x-15+2x-2
=5x-17
use the distribution property
Answer:
True
Step-by-step explanation:
Answer:
See below ↓
Step-by-step explanation:
The relation is :
- Let y = Motor Speed and x = Voltage
- y = 25x
<u>Title</u> : Variation of Motor Speed with Applied Voltage
<u>x-axis label</u> : Voltage (volt)
<u>y-axis label</u> : Motor speed (rpm)
As it constantly varies with a value of x and they are not isolated data points, they should be connected with a line.
