Question 184230
by substitution:
1.)
y=3x-4
y=-2x+1
simply substitute the value of y in the second equation to the first
-2x+1=3x-4
-2x-3x=-4-1
-5x=-5
(divide both sides by -5)
x=1
by elimination
-3x+y=-4
 2x+y=1
(subtract so that the sign of the subtrahend will be the opposite)
    -3x+y=-4
  -1(2x+y=1)-1


-3x+y=-4
-2x-y=-1

then add

-5x=-5
x=1
do the same with the others and try practicing.^^