The ratio given is 4:5 so you do 5divided by 20 which is 4 and multiply 4 and 4 and get 16 so your ratio is 16:20
Answer: 490 grams of the first alloy should be used.
30 grams of the second alloy should be used.
Step-by-step explanation:
Let x represent the weight of the first alloy in grams that should be used.
Let y represent the weight of the second alloy in grams that should be used.
A chemist has two alloys, one of which is 15% gold and 20% lead. This means that the amount of gold and lead in the first alloy is
0.15x and 0.2x
The second alloy contains 30% gold and 50% lead. This means that the amount of gold and lead in the second alloy is
0.3y and 0.5y
If the alloy to be made contains 82.5 g of gold, it means that
0.15x + 0.3y = 82.5 - - - - - - - - - - - -1
The second alloy would also contain 113 g of lead. This means that
0.2x + 0.5y = 113 - - - - - - - - - - - - -2
Multiplying equation 1 by 0.2 and equation 2 by 0.15, it becomes
0.03x + 0.06y = 16.5
0.03x + 0.075y = 16.95
Subtracting, it becomes
- 0.015y = - 0.45
y = - 0.45/- 0.015
y = 30
Substituting y = 30 into equation 1, it becomes
0.15x + 0.3 × 30 = 82.5
0.15x + 9 = 82.5
0.15x = 82.5 - 9 = 73.5
x = 73.5/0.15
x = 490
Answer:
the answer is 
, and - which is C.
Step-by-step explanation:
well I got that answer by doing this
we have 
= 5
For = f (a) the solutions are x = 
, -
so in this case the solutions are , and -
HOPE THIS HELPS :)
Answer:(gf)(3)=g(3)f(3) g(a)=3a+2 or g(3)=3(3)+2=9+2 =11 f(a)=2a−4 f(3)=2(3)−4=6−4=2 g(3)f(3)=112. Answer
Step-by-step explanation:
Answer:
ft³
Step-by-step explanation:
First, let's figure out how to get the <em>volume </em>of a sphere from its <em>surface area</em>. If r is the radius of our sphere, then
The formula for a sphere's surface area is 
The formula for a sphere's volume is 
So to get from area to volume, we have to <em>divide the area by 3 </em>and then <em>multiply it by r.</em> Mathematically:
Before we solve for V though, we need to find the radius of our sphere. Thankfully, we're given the surface area - 
ft² - so we can use the area formula to find that radius:
And now that we have our radius, we can put it into our volume formula to find
ft³
