What is the solution of #y = 3x - 4# and #2x - y = 1#?

Question

15381 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-06-04T13:45:20

#x=3, y=5#

Rearrange to make #y# the subject

#2x-y=1 =>y=2x-1#

Now you have two equations with #y=# so equate them

#3x-4=2x-1#

Add 4 to both sides

#3x=2x+3#

Subtract #2x# from both sides

#x=3#

Substitute #x=3# into #y=3x-4 => y=9-4, y=5#

Answer 2 · 2018-06-04T13:45:59

#x=3 and y=5#

Notice that there is a single #y# term in each equation,

Make #y# the subject in each case.

#color(blue)(y = 3x-4)" "and" "color(red)(y =2x-1)#

We know that #" "color(blue)(y) = color(red)(y)#

#:." "color(blue)( 3x-4)" "=" "color(red)(2x-1)#

#color(white)(xxxxxx)3x-2x = -1+4#

#color(white)(xxxxxxxxxxx)x = 3#

#y=2x-1#

#y = 2(3)-1 = 5#