Answer:
![x=2+\frac{1}{2}\sqrt[]{21}](https://tex.z-dn.net/?f=x%3D2%2B%5Cfrac%7B1%7D%7B2%7D%5Csqrt%5B%5D%7B21%7D)
or

Step-by-step explanation:

Add 21 on both sides.


a=4
b=-16
c=-5
![x=\frac{-b\frac{+}{}\sqrt[]{b^2-4ac} }{2a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7Bb%5E2-4ac%7D%20%20%7D%7B2a%7D)
![x=\frac{-(-16)\frac{+}{}\sqrt[]{(-16)^2-4(4)(-5)} }{2(4)}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-%28-16%29%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B%28-16%29%5E2-4%284%29%28-5%29%7D%20%20%7D%7B2%284%29%7D)
![x=\frac{16\frac{+}{}\sqrt[]{256+80} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B256%2B80%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}\sqrt[]{336} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B336%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}\sqrt[]{2^2*2^2*21} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D%5Csqrt%5B%5D%7B2%5E2%2A2%5E2%2A21%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}2*2\sqrt[]{21} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D2%2A2%5Csqrt%5B%5D%7B21%7D%20%20%7D%7B8%7D)
![x=\frac{16\frac{+}{}4\sqrt[]{21} }{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%5Cfrac%7B%2B%7D%7B%7D4%5Csqrt%5B%5D%7B21%7D%20%20%7D%7B8%7D)
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![x=\frac{16}{8}+\frac{4\sqrt[]{21}}{8}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%7D%7B8%7D%2B%5Cfrac%7B4%5Csqrt%5B%5D%7B21%7D%7D%7B8%7D)
![x=2+\frac{1}{2}\sqrt[]{21}](https://tex.z-dn.net/?f=x%3D2%2B%5Cfrac%7B1%7D%7B2%7D%5Csqrt%5B%5D%7B21%7D)
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![x=\frac{16}{8}-\frac{4\sqrt[]{21}}{8}\\x=2-\frac{1}{2}\sqrt{{21}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B16%7D%7B8%7D-%5Cfrac%7B4%5Csqrt%5B%5D%7B21%7D%7D%7B8%7D%5C%5Cx%3D2-%5Cfrac%7B1%7D%7B2%7D%5Csqrt%7B%7B21%7D)
Answer:
AC = 3.72 units
Angles:
A = 132.6°
C = 27.4°
Step-by-step explanation:
AC² = 5² + 8² - 2(5)(8)cos(20)
AC² = 13.82459034
AC = 3.718143399
3.718143399/sin20 = 8/sinA
sinA = 0.7358944647
A = 180 - 47.38285134
A = 132.6171487
3.718143399/sin20 = 5/sinC
sinC = 0.4599340405
C = 27.38285134
Well, a linear function is proportional, a straight line (on a graph). And the numbers must not have the same answer. For instance, if the X input is 5, and the Y output is 7. And then another X input is 5, and the Y output is 8, that's non-linear.
So, the Answer would be the third graph. This is because the X values are steadily increasing, and so are the Y values.
For the X and Y values, for each time X increases by 1, Y increases by -8. This is, linear because both sides are constantly and evenly increasing.
Answer:
1 meter.
Step-by-step explanation:
1 1/2 * 1/3
= 3/2 * 1/3
= 3/6
= 1/2.
So John used 2*1/2 = 1 meter of the ribbon.