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You can put this solution on YOUR website!
I see too many students making mistakes on problems like this because they plug numbers into the slope formula without any care as to whether their answer makes sense.
\n" ); document.write( "I think you will like math better if you understand what you are doing, rather than plugging numbers into formulas.
\n" ); document.write( "The slope of a line tells you how fast you go up or down as you move left to right along the line. The given slope of -4 means you go down 4 units every time you move one unit to the right.
\n" ); document.write( "So think about walking left to right between the two given points.
\n" ); document.write( "The point (-2,r) is to the left of (12,10), so you are starting at x=-2 and moving to x=12. How far do you move in the x direction? From -2 to +12, a change of 14.
\n" ); document.write( "The slope is -4, so you go down 4 units for each change of 1 in x. So when x changes by 14, y changes by 14(-4) = -56.
\n" ); document.write( "So you went down 56 units from a y value of \"r\" to a y value of 10. So what must the value of \"r\" be? 10+56 = 66.
\n" ); document.write( "When you get an answer for a problem like this in this way, you are doing the same arithmetic you would be doing if you plugged the numbers into the slope formula. But you will have a better understanding of what you are doing... and most likely you will be much less likely to get a wrong answer. \n" ); document.write( "