Is each line parallel, perpendicular or neither parallel or nor perpendicular to the line -x+4y=20? ? !

It's best to start by getting your equation into slope intercept form y=mx+b, where m is the slope

Given -x+4y=20, solve for y

4y=x+20

y=(1/4)x+5

If two lines are parallel, they will have the same slope. If two lines are perpendicular, they will have opposite reciprocal slopes (2/3 and -3/2, for example).

Solving for y, the first equation is y=(1/4)x+2. This has the same slope as the given equation, so the two are parallel.

The second equation is y=-4x-1, with -4 being the opposite reciprocal of 1/4. These two are perpendicular.

The third equation has slope -1/4, which is opposite but not the reciprocal, so it falls into the neither category.

The final equation also has slope -4, again the opposite reciprocal of 1/4. This line is perpendicular.

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: