y=9x+50 y=12x+20 solve by substitution

Thanks CPhill ^^ I earned more glasses :D

y = 9x + 50

y = 12x + 20

Because both equations equal 'y', they are equal to each other, leading to the following equation being true:

9x + 50 = 12x + 20

Simplify.

30 = 3x

10 = x

And now, substitute 'x' into either equation.

y = 9(10) + 50 = 90 + 50 = 140

Check.

y = 12(10) + 20 = 120 + 20 = 140

So x = 10, and y = 140

 Nice, GL ......  !!!!! ....  Your math skills have really improved.....