Can you help me...i'm not getting this

how does:
x+y=4 convert to y = -x+4

y+2=1/2x convert to y=1/2x-2


x-2y=-2 convert to y=1/2x+1

can someone explain & give examples on how to do these kind of problems....i dont get how to change it to the y= form

x+y=4 ----->then transpose x to the right side of the equation
y = -x+4 ----->x becomes negative, any number transposed to the opposite side must have the opposite sign

y+2=1/2x ----->then transpose 2 to the right side
y=1/2x-2 ----->2 becomes -2

x-2y=-2 ----->transpose x to the right
-2y=-2-x ----->x is now -x then divide both sides by -2 to get the value of y
y= (2+x)/2 ----> then separate the combined fraction. 2/2 and x/2
y = (x/2) + 1 ---->is the answer not y=1/2x+1

1)When an integer pass the equal sign its sign changes from positive to negative and vice versa

Ex : x + 2 = 0 , X = - 2

Ex : X - Y + 3 = 0 , X +3 = Y, X = Y - 3
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2) When a fraction number pass the equal sign : it is powered by negative 1
and multiplied by - 1
In another way :

switch the numerator with the dominator

Ex : x + 1/2 = 0

pass the 1/2 to the other side

change the sign => -1/2

Switch the dominator and the numerator => - 2 / 1

if you want to get y by itself then you need to equally change both sides of the equation.

x+y=4

so you would subtract x from both sides since x-x=0

x+y+(-x)=4+(-x)

notice that BOTH sides must have the same exact thing done to them.

then you simplify

y=4-x or y=-x+4


subtract 2 from the secont one to get y alone.

the third one my be a little more difficult though.

first remove all digits not attached to the y

x-2y+(-x)=-2+(-x)

simplify

-2y=-x-2

then divide or multiply both sides equally

-2y(-1/2)= (-x-2)(-1/2) or -x(-1/2) -2(-1/2)

y= 1/2x+1

First Question:
Subtract x from both sides

Second Question:
Subtract 2 from both sides

Third Question:
Subtract x from both sides then divide both sides by -2

the first one you just minus x
the second you minus 2 and
the third you minus x and divide all by 2