The point (2,-1) is on the line2x+y=5

Nope its not on the line

Step-by-step explanation:

2x+y=5

2(2)+(-1)=5

3=5

which is not true

For this equation to be true y has to equal 1 if x is 2 and the equation would go like this:

2x+y=5

2(2)+1=5

5=5

True

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)