How many soultions does this linear system have? y=2x-5 -8x-4y=-20 ?

One solution, since the lines intersect at only one point.

Step-by-step explanation:

These two equations should be separated by a comma or written on two separate lines.  I'm assuming that you meant:

y=2x-5

-8x-4y=-20

First, we need to ensure that both of these equations are written in the same format, y = mx + b.  The first equation is already in that format:  y = 2x - 5.  The  first step in rewriting the second equation is to add 8x to both sides:

+ 8x -8x -4y = 8x = -20, or -4y = 8x - 20.

Next, we divide all three terms by -4 to isolate y:

y = -2x + 5

Then the given system is equivalent to

y = 2x - 5

y = -2x + 5

We could either solve this system or analyze it without solving it:

Because these two equations have different slopes, their graphs are not parallel.  This indicates that the lines intersect at only one point.

6.5

step-by-step explanation:

you said it was in the question

~courtney