- 1 1/3 - 2 1/5
= -4/3 - 11/5
= -20/15 - 33/15
= -53/15
= -3 8/15 mg/L
Answer:
3.62
Step-by-step explanation:
I used a calculator. But on the bottom, it says the rounded number should only have 3 digits. The real answer is 3.622580645. But since I rounded the answer would be 3.62.
Hope this helps!
Hello!
The graph y < -2/3x + 2 has a dotted line. That means that any points on the dotted line or not shaded, is not a solution to this inequality. Since we are given 4 choices, we can substitute those values into the given inequality to see if it is true.
A) (0, 2)
2 < -2/3(0) + 2
2 < 2, this is false.
B) (3, 0)
0 < -2/3(3) + 2
0 < -2 + 2
0 < 0, this is false.
C) (0, 0)
0 < -2/3(0) + 2
0 < 2, this is true.
D). (0, 3)
3 < -2/3(0) + 2
3 < 2, this is false.
To check if choice C) (0, 0) is true, we should look at the given graph.
Since (0, 0) is in the shaded area, and is not graphed on the dotted line, therefore, a solution to this linear inequality is C, (0, 0).
Answer:
12.1 cm
Step-by-step explanation:
Using the law of sines, we can find angle C. Then from the sum of angles, we can find angle B. The law of sines again will tell us the length AC.
sin(C)/c = sin(A)/a
C = arcsin((c/a)sin(A)) = arcsin(8.2/13.5·sin(81°)) ≈ 36.86°
Then angle B is ...
B = 180° -A -C = 180° -81° -36.86° = 62.14°
and side b is ...
b/sin(B) = a/sin(A)
b = a·sin(B)/sin(A) = 13.5·sin(62.14°)/sin(81°) ≈ 12.0835
The length of AC is about 12.1 cm.
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<em>Comment on the solution</em>
The problem can also be solved using the law of cosines. The equation is ...
13.5² = 8.2² +b² -2·8.2·b·cos(81°)
This is a quadratic in b. Its solution can be found using the quadratic formula or by completing the square.
b = 8.2·cos(81°) +√(13.5² -8.2² +(8.2·cos(81°))²)
b = 8.2·cos(81°) +√(13.5² -(8.2·sin(81°))²) . . . . . simplified a bit
