2 answers:
It is 30 degrees. Add 90 and 60 to get 180. Then subtract that from 180, since all triangles interior angles add to 180. You’ll get 30.
Answer:
![6\sqrt{3](https://tex.z-dn.net/?f=6%5Csqrt%7B3)
Step-by-step explanation:
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Step by step step by step equations
Answer:
x^2 +18x +80
= x^2 + 10x + 8x +80
= x(x+10) + 8(x+10)
= (x+10)(x+8)
Hope this help!
Good luck!
Answer:C=2πr=2·π·2≈12.56637in
Step-by-step explanation:
21 and 1 because both numbers are odd
Answer:
![\dfrac{7}{9}](https://tex.z-dn.net/?f=%5Cdfrac%7B7%7D%7B9%7D)
Step-by-step explanation:
![\dfrac{x+1}{y+1}=\dfrac{4}{5}\\\Rightarrow 5x-4y=-1](https://tex.z-dn.net/?f=%5Cdfrac%7Bx%2B1%7D%7By%2B1%7D%3D%5Cdfrac%7B4%7D%7B5%7D%5C%5C%5CRightarrow%205x-4y%3D-1)
![\dfrac{x-5}{y-5}=\dfrac{1}{2}\\\Rightarrow 2x-y=5](https://tex.z-dn.net/?f=%5Cdfrac%7Bx-5%7D%7By-5%7D%3D%5Cdfrac%7B1%7D%7B2%7D%5C%5C%5CRightarrow%202x-y%3D5)
Putting it in matrix form
![\begin{bmatrix}a_{1}&b_{1}\\a_{2}&b_{2}\end{bmatrix}{\begin{bmatrix}x\\y\end{bmatrix}=\begin{bmatrix}{c_{1}}\\{c_{2}}\end{bmatrix}\\\Rightarrow\begin{bmatrix}5 & -4\\2 & -1\end{bmatrix}\begin{bmatrix}x\\ y\end{bmatrix}=\begin{bmatrix}-1\\ 5\end{bmatrix}](https://tex.z-dn.net/?f=%5Cbegin%7Bbmatrix%7Da_%7B1%7D%26b_%7B1%7D%5C%5Ca_%7B2%7D%26b_%7B2%7D%5Cend%7Bbmatrix%7D%7B%5Cbegin%7Bbmatrix%7Dx%5C%5Cy%5Cend%7Bbmatrix%7D%3D%5Cbegin%7Bbmatrix%7D%7Bc_%7B1%7D%7D%5C%5C%7Bc_%7B2%7D%7D%5Cend%7Bbmatrix%7D%5C%5C%5CRightarrow%5Cbegin%7Bbmatrix%7D5%20%26%20-4%5C%5C2%20%26%20-1%5Cend%7Bbmatrix%7D%5Cbegin%7Bbmatrix%7Dx%5C%5C%20y%5Cend%7Bbmatrix%7D%3D%5Cbegin%7Bbmatrix%7D-1%5C%5C%205%5Cend%7Bbmatrix%7D)
From Cramer's rule we have
![x=\dfrac{\begin{vmatrix}c_1 &b_1 \\ c_2 & b_2\end{vmatrix}}{\begin{vmatrix}a_1 &b_1 \\ a_2& b_2\end{vmatrix}}\\\Rightarrow x=\dfrac{\begin{vmatrix}-1 &-4 \\ 5 & -1\end{vmatrix}}{\begin{vmatrix}5 &-4 \\ 2& -1\end{vmatrix}}\\\Rightarrow x=\dfrac{1+20}{-5+8}\\\Rightarrow x=7](https://tex.z-dn.net/?f=x%3D%5Cdfrac%7B%5Cbegin%7Bvmatrix%7Dc_1%20%26b_1%20%5C%5C%20c_2%20%26%20b_2%5Cend%7Bvmatrix%7D%7D%7B%5Cbegin%7Bvmatrix%7Da_1%20%26b_1%20%5C%5C%20a_2%26%20b_2%5Cend%7Bvmatrix%7D%7D%5C%5C%5CRightarrow%20x%3D%5Cdfrac%7B%5Cbegin%7Bvmatrix%7D-1%20%26-4%20%5C%5C%205%20%26%20-1%5Cend%7Bvmatrix%7D%7D%7B%5Cbegin%7Bvmatrix%7D5%20%26-4%20%5C%5C%202%26%20-1%5Cend%7Bvmatrix%7D%7D%5C%5C%5CRightarrow%20x%3D%5Cdfrac%7B1%2B20%7D%7B-5%2B8%7D%5C%5C%5CRightarrow%20x%3D7)
![y=\dfrac{\begin{vmatrix}a_1 &c_1 \\ a_2 & c_1\end{vmatrix}}{\begin{vmatrix}a_1 &b_1 \\ a_2& b_2\end{vmatrix}}\\\Rightarrow y=\dfrac{\begin{vmatrix}5 &-1 \\ 2 & 5\end{vmatrix}}{\begin{vmatrix}5 &-4 \\ 2& -1 \end{vmatrix}}\\\Rightarrow y=\dfrac{25+2}{-5+8}\\\Rightarrow y=9](https://tex.z-dn.net/?f=y%3D%5Cdfrac%7B%5Cbegin%7Bvmatrix%7Da_1%20%26c_1%20%5C%5C%20a_2%20%26%20c_1%5Cend%7Bvmatrix%7D%7D%7B%5Cbegin%7Bvmatrix%7Da_1%20%26b_1%20%5C%5C%20a_2%26%20b_2%5Cend%7Bvmatrix%7D%7D%5C%5C%5CRightarrow%20y%3D%5Cdfrac%7B%5Cbegin%7Bvmatrix%7D5%20%26-1%20%5C%5C%202%20%26%205%5Cend%7Bvmatrix%7D%7D%7B%5Cbegin%7Bvmatrix%7D5%20%26-4%20%5C%5C%202%26%20-1%20%5Cend%7Bvmatrix%7D%7D%5C%5C%5CRightarrow%20y%3D%5Cdfrac%7B25%2B2%7D%7B-5%2B8%7D%5C%5C%5CRightarrow%20y%3D9)
Verifying the results
![\dfrac{7+1}{9+1}=\dfrac{8}{10}=\dfrac{4}{5}](https://tex.z-dn.net/?f=%5Cdfrac%7B7%2B1%7D%7B9%2B1%7D%3D%5Cdfrac%7B8%7D%7B10%7D%3D%5Cdfrac%7B4%7D%7B5%7D)
![\dfrac{7-5}{9-5}=\dfrac{2}{4}=\dfrac{1}{2}](https://tex.z-dn.net/?f=%5Cdfrac%7B7-5%7D%7B9-5%7D%3D%5Cdfrac%7B2%7D%7B4%7D%3D%5Cdfrac%7B1%7D%7B2%7D)
Hence, the fraction is
.