Question 772958: I am very unsure how to do equation of a straight line? I find all the letters and numbers really confusing and i do not understand where half the numbers come from.for example: point (-2,7), gradient=1/2. it says the answer is y-7=1/2 (x-(-2)), x=2y=16=0. where does the 16 come from?
Answer by josgarithmetic(39617)   (Show Source):
You can put this solution on YOUR website! The answer shows the use of Point-slope form for a line. "Gradient" possibly means, "slope".
Slope for a line means VERTICAL CHANGE DIVIDED BY HORIZONTAL CHANGE. Based on this, what you seem to have as slope, m, is like:
 .
You KNOW the slope is (1/2), and you KNOW that one of the points of the line is (-2,7).
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More generally, if you have a line with variable point (x,y) and particular point (u,v), then the slope is 
You can use the definition of slope to fill the information for the slope and the one given point, and then this IS the equation for the line. You then simplify this equation and put into whichever form you need.
Look again now at the red-outlined equation for the slope of YOUR line and simplify that.
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