<span>85% ethanol | 25% ethanol | 50% ethanol
x | y | 20 gal
use x and y because you don;t know how much she needs.
0.85x | 0.25y | 20(0.5)
85% is 85/100 or 0.85, and you need that much of x, same goes for the 25% and 50% mixtures so now you can make up 2 equations
1) x + y = 20 2) 0.85x + 0.25y= 10 (you get 10 when you multiply 20 by 0.5) now you can solve for x or y using substitution.
first rewrite 1) in terms of x or y: x+ y= 20 ----> y= 20 - x now you can substitute 20- x for y in the second equation.. 0.85x + 0.25y= 10 0.85x + 0.25(20-x)= 10 distribute here..(0.25 * 20 and 0.25 * (-x) ) 0.85x + 5 - 0.25x = 10 combine like terms 0.6x +5 = 10 move the 5 over to the other side 0.6x= 10 -5 0.6x = 5 divide both sides by 0.6 x= 25/3 or 8.3 now you know the amount of x so you can substitue this back into the first equation to find y. 0.85x + 0.25y= 10 0.85(25/3) +0.25y= 10 85/12 + 0.25y= 10 0.25y = 10- 85/12 0.25y= 35/12 y= 35/3 or 11.6 you can check by putting these values into the euations: 1) x+ y= 20 25/3 + 35/3 =20 20= 20 good so far 2) 0.85x + 0.25y= 10 0.85(25/3) + 0.25(35/3)=10 10 = 10
so our values for x and y work
x= 25/3 and y= 35/3</span>
Answer:
<u>Physical Properties</u>
1. Metals are shiny but most non - metals lack this property.
2. Metals are able to deform under compression (malleable) but most non - metals lack this property.
<u>Chemical Properties</u>
<u>1</u><u>.</u><u> </u><u>Metal</u><u>s</u><u> </u><u>are</u><u> </u><u>good</u><u> </u><u>conductors</u><u>of</u><u> </u><u>heat</u><u> </u><u>and</u><u> </u><u>electricity</u><u> </u><u>but</u><u> </u><u>most</u><u> </u><u>non</u><u> </u><u>-</u><u> </u><u>metals</u><u> </u><u>are</u><u> </u><u>insulators</u><u>.</u>
<u>2</u><u>.</u><u> </u><u>Metals</u><u>,</u><u> </u><u>when</u><u> </u><u>exposed</u><u> </u><u>to</u><u> </u><u>water</u><u> </u><u>atmospheric</u><u> </u><u>oxygen</u><u> </u><u>tend</u><u> </u><u>to</u><u> </u><u>rust</u><u> </u><u>but</u><u> </u><u>non</u><u> </u><u>-</u><u> </u><u>metals</u><u> </u><u>lack</u><u> </u><u>this</u><u> </u><u>chemical</u><u> </u><u>property</u>
Reflection, refracting, and the energy levels of molecular orbitals
<h3><u>Answer</u>;</h3>
Concave Lenses
<h3><u>Explanation</u>;</h3>
- A concave lens is thin in the middle and thick at the edges, such that it seems to cave inwards. It spreads light rays apart producing an image smaller than the actual object.
- <em><u>Images formed by a concave lens are virtual, upright, reduced in size and located on the same side of the lens as the object. Diverging lenses or concave lens always produce images that share these characteristics. The location of the object does not affect the characteristics of the image. </u></em>