Solve for y intercepts

Question

7x+y=-2
Answer: Y = -2

7x + 2y = 4
Answer: Y = 2
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If (3,-5) is a point on the graph for the equation in the form y=mx+7, then m=?

Answer:
-5=m(3)=7
m=-4
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Identify slope and y - intercept
y=7x+3
Answer: slope=7 y intercept=3

4x-y =0
Ans: slope =4 y intercept = 0
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Solve for r
(1,r) (3,-5) are two points on a line with slope -4.
Find r
Answer:
r = (-5 - r)/( 3-1 )
r= 3
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Write the slope intercept for of the equation:
>slope = -5/4 , y intercept = -4
Ans: y = -5/4x - 4

>Through (-1,4), slope = -2
Ans: y = -2x +2

>Through (4,2) and (0,4)
Ans y= 1/2x -4
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Write the slope intercept form of the equation of the line described:
Through (-1,2), parallel to y = -x - 1

Answer: y = -x + 1
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Answer 1

all look good except this one:

>Through (4,2) and (0,4)
Ans y= 1/2x -4

from given: y = mx + 4
plug in the given point:
2 = 4m + 4
-2 = 4m
m = -1/2

so y = (-1/2)x + 4

notice both (4,2) and (0,4) satisfy my equation.