posted by kevin on .
im learnin about y=mx+b
1.describe the line you think each equation represent
Y=x, y=5, x=-3
2. The equation of a line is y=mx+2. determione the value of m when the line passes through each pint
The best way to do question 1 is to draw a graph of each. Draw your x, y axes, then find two points on each of the lines, then use a ruler to draw the line that they're both on.
Which two points? Any two will do, but it's easier to draw if they're not too close together.
Take y=x. Pick a number, any number, say 2. When x=2, what is y? Well y=x and x=2 so y=2, so you have the point (2,2) Another point, say 0. When x is zero, y is zero, so now you have (0,0), the origin. Plot both points, draw a line between, and going off into the distance at both ends. Now describe that line.
y = mx + 2. All we have to do is substitute the point values for x and y, and solve for m. I'll do the first one, (12,5):
y = mx + 2
5 = m*12 + 2
Subtract 2 from both sides:
m*12 = 3
Divide across by 12:
m = 3/12 = 1/4