What is the solution to the system?

For the first line we have a slope of (y2-y1)/(x2-x1)

(2--2)/(1--1)=4/2=2 so we have:

y=2x+b, now solve for b with either of the points, I'll use: (1,2)

2=2(1)+b

b=0 so the first line is:

y=2x

Now the second line:

(1-10)/(4--2)=-9/6=-3/2 so far then we have:

y=-3x/2+b, using point (4,1) we solve for b...

1=-3(4)/2+b

1=-6+b

b=7 so 

y=-3x/2+7 or more neatly...

y=(-3x+14)/2

...

The solution occurs when both the x and y coordinates for each are equal, so we can say y=y, and use our two line equations...

2x=(-3x+14)/2

4x=-3x+14

7x=14

x=2, and using y=2x we see that:

y=2(2)=4, so the solution occurs at the point:

(2,4)

The principal, real, root of: 50−−√2=7.071067817.07106781−7.0710678150 is not a perfect square