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Chapter 7.6 Finding an Equation of a line. Kimberly Sung Period 2 3/18/2013. Things to Know and Remember. The slope-intercept equation is y= mx+b The ‘m’ is the slope The ‘b’ is the y –intercept The equation to find the slope is m= difference of y coordinates
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Chapter 7.6 Finding an Equation of a line Kimberly Sung Period 2 3/18/2013
Things to Know and Remember • The slope-intercept equation is y=mx+b • The ‘m’ is the slope • The ‘b’ is the y –intercept • The equation to find the slope is m= difference of y coordinates difference of x coordinates • The point-slope equation is y-y1 = m (x-x1)
Write an equation for each line with the given point and slope. Express equation in point slope formula. (0,3), m=-3 • y=mx+b • 3=-3(0)+b • 3=0+b • b=3 • y=-3x+3 • Equation. • Substitute. • Take care of parentheses. • Simplify • Plug the original slope and the answer for ‘b’ back into the equation.
(0,6) (-4,0) Locate the points. 6 - 0 = 6 = 3 0- -4 = 4 2 Find the slope. y=mx+b Equation. 6= 3/2 (0) +b Pick the easiest point to substitute. 6=0+b Take care of parentheses. b=6 Simplify y=3/2 (x) +6 Plug in the slope and the solution to ‘b’. Write an equation for each line in slope intercept form.
Write an equation for each line that contains the given pair of points. (5,0) (0,2) • 0--2 =2 2 5 -0 =5 = 5 • (y--2)= 2/5 (x-0) • y+2=2/5(x) -0 • y+2=2/5(x) • -2 -2 • y=2/5(x)-2 • Find the slope • Substitute with the slope and the simplest point • Distribute on the right side and subtract on the left • Simplify • Subtract on both sides • Solution
Problem pg. and number 1st problem~ textbook pg. 331 #7 2nd problem~ textbook pg. 331 #25 3rd problem~ textbook pg. 331 #19