How many solutions does the system have?
y = 3x + 9
y = -1/2x - 1

Question

How many solutions does the system have?
y = 3x + 9
y = -1/2x - 1

anonymous · Answer

Set the first function equal to the second function:
3x + 9 = -1/2 - 1
And solve for x :)

texaschic101 · Answer

there is different slopes and different y intercepts......I would say 1 solution......but wait and see what phi says...he is smarter then me

phi · Answer

notice that both equations are equations of a line

if two lines are not parallel  (i.e. do not have the same slope) they meet only once (where they cross)

phi · Answer

and to be the clear,  the (x,y) point that is on both lines (where the cross) is *the* solution

texaschic101 · Answer

well said,  phi :)

anonymous · Answer

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1 exception is of both equations are a different equation for the exact same line, in which case the lines have infinite solutions (they are literately on top of each other, so they always cross)