Nobody understands maths and if you do you were sent from heaven
You need $315 worth of sales, if I'm right. $100-30 is $70. 70/x=2/9. 70x9=630/2=315.
Option B 6x-7y = -11 is correct
Step-by-step explanation:
We need to write the equation of the given line in standard form.
The points are (1/2,2) and (3,1)
The equation used is:
![y-y_{1}=m(x-x_{1})](https://tex.z-dn.net/?f=y-y_%7B1%7D%3Dm%28x-x_%7B1%7D%29)
where m is the slope.
Finding slope :
![m = \frac{y_{2}-y_{1}}{x_{2}-x_{1}}](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7By_%7B2%7D-y_%7B1%7D%7D%7Bx_%7B2%7D-x_%7B1%7D%7D)
x₁= 1/2, y₁=2, x₂=-3, y₂=-1
Putting values:
![m=\frac{-1-2}{-3-1/2} \\m=\frac{6}{7}](https://tex.z-dn.net/?f=m%3D%5Cfrac%7B-1-2%7D%7B-3-1%2F2%7D%20%5C%5Cm%3D%5Cfrac%7B6%7D%7B7%7D)
Now taking point (1/2,2) and s;ope m = 6/7 finding equation:
![y-y_{1}=m(x-x_{1})](https://tex.z-dn.net/?f=y-y_%7B1%7D%3Dm%28x-x_%7B1%7D%29)
![y-2=\frac{6}{7}(x-\frac{1}{2})\\ 7(y-2)=6(x-\frac{1}{2})\\7y-14=6x-3\\7y-6x=-3+14\\7y-6x= 11\\Multiply \,\,with\,\, -1\\-7y+6x=-11\\6x-7y=-11](https://tex.z-dn.net/?f=y-2%3D%5Cfrac%7B6%7D%7B7%7D%28x-%5Cfrac%7B1%7D%7B2%7D%29%5C%5C%20%207%28y-2%29%3D6%28x-%5Cfrac%7B1%7D%7B2%7D%29%5C%5C7y-14%3D6x-3%5C%5C7y-6x%3D-3%2B14%5C%5C7y-6x%3D%2011%5C%5CMultiply%20%5C%2C%5C%2Cwith%5C%2C%5C%2C%20-1%5C%5C-7y%2B6x%3D-11%5C%5C6x-7y%3D-11)
So, Option B 6x-7y=-11 is correct
Keywords: Standard form of equation
Learn more about Standard form of equation at:
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Answer:
$40 in euros!
Step-by-step explanation: