Firstly, we can look at our givens,
a = 17
b = 22
c = 30
And we are looking for m∠A
Is the Law of Cosines. Now we can solve for our unknown, m∠A. This will give us
![A = cos^{-1} (\frac{-a^2+b^2+c^2}{2bc})](https://tex.z-dn.net/?f=A%20%3D%20cos%5E%7B-1%7D%20%28%5Cfrac%7B-a%5E2%2Bb%5E2%2Bc%5E2%7D%7B2bc%7D%29)
Now we can substitute in our given variables.
![A= cos^{-1} (\frac{-(17^2)+27^2+30^2}{2(27)(30)} )](https://tex.z-dn.net/?f=A%3D%20cos%5E%7B-1%7D%20%28%5Cfrac%7B-%2817%5E2%29%2B27%5E2%2B30%5E2%7D%7B2%2827%29%2830%29%7D%20%29)
Then we can plug this into our calculator which will give us
34.19185257 degrees
Now we just have to round to the nearest tenth
This means that the answer is 34.2 degrees
Try this solution (see the attachment).
After solving the system of equations, x= -3 and y=6
Step-by-step explanation:
We need to solve the following system of equations by substitution.
![-3x + y = 15\,\,\,(1)\\-8x-7y = -18\,\,\,(2)](https://tex.z-dn.net/?f=-3x%20%2B%20y%20%3D%2015%5C%2C%5C%2C%5C%2C%281%29%5C%5C-8x-7y%20%3D%20-18%5C%2C%5C%2C%5C%2C%282%29)
Finding value of y from equation(1) and substituting it in equation(2)
![y=15+3x\\substituting\,\,in\,\,equation(2)\\-8x-7(15+3x)=-18\\Solving:\\-8x-105-21x=-18\\-8x-21x=-18+105\\-29x=87\\x=\frac{87}{-29}\\x=-3\\](https://tex.z-dn.net/?f=y%3D15%2B3x%5C%5Csubstituting%5C%2C%5C%2Cin%5C%2C%5C%2Cequation%282%29%5C%5C-8x-7%2815%2B3x%29%3D-18%5C%5CSolving%3A%5C%5C-8x-105-21x%3D-18%5C%5C-8x-21x%3D-18%2B105%5C%5C-29x%3D87%5C%5Cx%3D%5Cfrac%7B87%7D%7B-29%7D%5C%5Cx%3D-3%5C%5C)
The value of x is x=-3
Now, Finding value of x from eq(1) and substituting in equation(2)
![-3x=15-y\\x=\frac{15-y}{-3}\\Substituting\,\,in\,\,equation(2)\\-8(\frac{15-y}{-3})-7y=-18\\\frac{120-8y}{3}-7y=-18\\\frac{120-8y-7y*3}{3}=-18\\\frac{120-8y-21y}{3}=-18\\\frac{120-29y}{3}=-18\\120-29y=-18*3\\120-29y=-54\\-29y=-54-120\\-29y=-174\\y=\frac{-174}{-29}\\y=6](https://tex.z-dn.net/?f=-3x%3D15-y%5C%5Cx%3D%5Cfrac%7B15-y%7D%7B-3%7D%5C%5CSubstituting%5C%2C%5C%2Cin%5C%2C%5C%2Cequation%282%29%5C%5C-8%28%5Cfrac%7B15-y%7D%7B-3%7D%29-7y%3D-18%5C%5C%5Cfrac%7B120-8y%7D%7B3%7D-7y%3D-18%5C%5C%5Cfrac%7B120-8y-7y%2A3%7D%7B3%7D%3D-18%5C%5C%5Cfrac%7B120-8y-21y%7D%7B3%7D%3D-18%5C%5C%5Cfrac%7B120-29y%7D%7B3%7D%3D-18%5C%5C120-29y%3D-18%2A3%5C%5C120-29y%3D-54%5C%5C-29y%3D-54-120%5C%5C-29y%3D-174%5C%5Cy%3D%5Cfrac%7B-174%7D%7B-29%7D%5C%5Cy%3D6)
So, Value of y is y=6
After solving the system of equations, x= -3 and y=6
Keywords: system of equations
Learn more about system of equations at:
#learnwithBrainly
Answer: Cant nobody help you
Step-by-step explanation:Beacuse you cant read that its to small