Writing Linear Equations Day 3 Algebra 1 Review

Write the Linear Equation

Write the Linear Equation X 4 8 12 Y 30 24 18

Write the Linear Equation Find the equation of the line that passes through (4, -4) and (8, -3).

Write the Linear Equation X 50 60 70 Y 35 40 45

Parallel Lines • Two non-vertical lines are parallel if and only if their slopes are equal. m 1 l 1 MAP TAP 2003 -2004 Parallel and Perpendicular Lines m 2 l 2 6

Write the equation of the line that passes through (3, 6) and is parallel to y = 2/3 x+2. m = 2/3 and the point is (3, 6) y = mx+b 6 = 2/3(3)+b 6 = 2+b 4=b y = 2/3 x+4 MAP TAP 2003 -2004 Parallel and Perpendicular Lines 7

Write the equation of the line that passes through (4, -5) and is parallel to 2 x + y = -4. m = -2 and the point is (4, -5) y = mx+b -5 = -2(4)+b -5 = -8+b 3=b y = -2 x+3 MAP TAP 2003 -2004 Parallel and Perpendicular Lines 8

Write the equation of the line that passes through (-6, 4) and is parallel to y=1/3 x-1. m=1/3 and the point is (-6, 4) y =1/3 x+6 MAP TAP 2003 -2004 Parallel and Perpendicular Lines 9

Perpendicular Lines • Two lines are perpendicular if and only if the product of their slopes is -1. Slopes are negative reciprocals MAP TAP 2003 -2004 Parallel and Perpendicular Lines l 1 l 2 m 1 m 2 10

Find the slope of the perpendicular line

Write the equation of the line that passes through (6, -5) and is perpendicular to y = 2 x+3. m = -1/2 and the point is (6, -5) y = mx+b -5 = -1/2(6)+b -5 = -3+b -2 = b y = -1/2 x-2 MAP TAP 2003 -2004 Parallel and Perpendicular Lines 12

Write the equation of the line that passes through (6, -7) and is perpendicular to y = 2/3 x+1. m = -3/2 and the point is (6, -7) y = mx+b -7 = -3/2(6)+b -7 = -9+b 2=b y = -3/2 x+2 MAP TAP 2003 -2004 Parallel and Perpendicular Lines 13

Write the equation of the line that passes through (4, -3) and is perpendicular to y = x+6. m = -1 and the point is (-4, -3) y = -x-7 MAP TAP 2003 -2004 Parallel and Perpendicular Lines 14

Exit Slip Your Name 1) Find the equation of a line that passes through (3, 7) and (-1, -9). 2) Find the equation of a line that is perpendicular to y = -3 x + 4 and passes through the point (9, 5). 3) Find the equation from the table: