What you want to do, is isolate the y by itself to rewrite the equation as y=mx+b. So when you move the 5x over the equation looks like this -6y=-5x+30. Then you divide the -5x+30 by -6 to isolate the y. Thus making the equation y=5/6x-5. And since there is only one answer with the y-intercept as (0,-5); The answer is A.
Ok to find dy/dx of x+2y=xy we take derivative of both sides with respect to x
1+2dy/dx = x*dy/dx +y*dx/dx
1+ 2dy/dx = x*dy/dx + y* 1
2dy/dx +1 = x*dy/dx + y
2y’ + 1 = xy’ + y
2y’ + 1 - xy’ = y
2y’ -xy’ = y - 1
y’(2-x) = y - 1
so we get finally
y’= (y-1)/(2-x)
Hope this helps you understand the concept! Any questions please ask! Thank you so much!!
Answer:

small cups=30
large cups=40
Step-by-step explanation:
let x be the number of small cups and y the number of large cups.
-Given that 10 more cups than small cups of lemonade were sold:

#Before the 10 more were sold, the number of x and y sold were equal>

The number of small cups sold was 30
#Since, the number of large cups was 10 more, y=x+10=30+10=40
Answer:
{x,y} = {19/12,5/6}
Step-by-step explanation:
Honestly just use desmos or mathyway