Answer:
The volume of hemisphere is <u>19.4 cubic meter</u>.
Step-by-step explanation:
Given:
A hemisphere is with a radius of 2.1 m.
Now, to find the hemisphere volume with radius 2.1 m.

So, we put formula to get the volume of hemisphere:

<u><em>Hence, the rounded to the nearest tenth of a cubic meter is 19.4 cubic meter.</em></u>
Therefore, the volume of hemisphere is 19.4 cubic meter.
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:
11
Step-by-step explanation:
f(3)=(3)^2+2(3)-4
f(3)=9+2(3)-4
f(3)=9+6-4
f(3)=15-4
f(3)=11
Answer:
15/31
Step-by-step explanation:
substitute -9 were there's x in the function
f(-9)=2(-9)+3/4(-9)+5
=-18+3/-36+5
=-15/-31
the negatives cancel giving you
15/31
Answer: X = 42
Steps:
(3x + 12) + x = 180
3x + 12 + x = 180
4x + 12 = 180
4x = 180 - 12
4x = 168
x = 168/4
x = 42
Check:
(3x + 12) + x = 180
3x + 12 + x = 180
3(42) + 12 + 42 = 180
126 + 12 + 42 = 180
180 = 180 ✅
I would appreciate the brainliest if this was correct and had helpful & clear steps! :)