28 , i think :) I hope it’s correct and good luck
Answer:
x= 3
y=2
Step-by-step explanation:
-3x + 9y = 9 ----------- equation 1
3x + 2y = 13--------------- equation 2
In Matrix Form
![\left[\begin{array}{cc}-3&9\\3&2\end{array}\right] \left[\begin{array}{c}x\\y\end{array}\right] = \left[\begin{array}{c}9\\13\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-3%269%5C%5C3%262%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D9%5C%5C13%5Cend%7Barray%7D%5Cright%5D)
Let A = ![\left[\begin{array}{cc}-3&9\\3&2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-3%269%5C%5C3%262%5Cend%7Barray%7D%5Cright%5D)
X = ![\left[\begin{array}{c}x\\y\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D)
and B = ![\left[\begin{array}{c}9\\13\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D9%5C%5C13%5Cend%7Barray%7D%5Cright%5D)
Then Mathematically AX= B
or X= A⁻¹ B
Where A⁻¹ = Adjacent A/ mod of A
Adjacent A = ![\left[\begin{array}{cc}2&-9\\-3&-3\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D2%26-9%5C%5C-3%26-3%5Cend%7Barray%7D%5Cright%5D)
Mod Of A= -6 - (27) = -33 which is not equal to zero
so Putting These values in the given formula
X= 1/-33
Now Multiplying Rows and Columns
= -1/33 ![\left[\begin{array}{cc}2*9+- 9*13\\-3*9 +- 3*13\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D2%2A9%2B-%209%2A13%5C%5C-3%2A9%20%2B-%203%2A13%5Cend%7Barray%7D%5Cright%5D)
Solving the Matrix we get
= -1/33 ![\left[\begin{array}{cc}18-117\\-27-39\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D18-117%5C%5C-27-39%5C%5C%5Cend%7Barray%7D%5Cright%5D)
= -1/33 ![\left[\begin{array}{cc}-99\\-66\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-99%5C%5C-66%5Cend%7Barray%7D%5Cright%5D)
From Here we find x= 99/33 or 3
and y = 66/33= 2
<u><em>Answer:</em></u>
∠7 = 95°
<u><em>Explanation:</em></u>
<u>1- getting the value of x:</u>
In the given figure, angle 1 and angle 4 are vertically opposite angles.
Therefore, they are equal in measurement
This means that:
3x + 10 = 4x - 15
4x - 3x = 10 + 15
x = 25
<u>2- getting the value of angle 4:</u>
We know that:
x = 25 and ∠4 is 4x-15
This means that:
∠4 = 4(25) - 15
∠4 = 85°
<u>3- getting the value of ∠6:</u>
From the given figure, we can see that ∠4 and ∠6 are supplement angles, this means that their summation is 180°.
We have calculated that ∠4 is 85°, therefore:
180 = ∠4 + ∠6
∠6 = 180 - ∠4
∠6 = 180 - 85
∠6 = 95°
<u>4- getting the value of angle 7:</u>
From the drawing, we can note that ∠6 and ∠7 are vertically opposite angles. This means that they are equal in measurements.
Therefore:
∠7 = ∠6 = 95°
Hope this helps :)
0.2:1
I divided 3 by 15 and got 0.2 and then divided 15 by 15 to get one
