Algebra 5.6 Standard Form Different Forms of Linear Equations SI Form PS Form Vertical Line Horizontal Line Standard Form y = mx + b y – y1 = m(x – x1) x=# y=# Ax + By = C -A and B are both not 0 -A and B are integers and A is positive We try! Write y= 2 x–3 in Standard Form 5 5[y = 2 x – 3]5 First clear the fraction. 5 5y = 2x -15 -2x -2x Then get x and y on the left side. -1[-2x + 5y = -15] -1 Then get the coefficient of x positive. 2x - 5y = 15 You try! Write -5x + 11 = ½ y in Standard Form 2 [-5x + 11 = ½ y] 2 First clear the fraction. -10x + 22 = y +10x +10x Then get x and y on the same side. 22 = 10x + y Next rewrite with x and y on the left. 10x + y = 22 We try! Write the standard form of an equation of the line passing through (-4, 3) with a slope of -2. y – 3 = -2(x + 4) First write in PS form and distribute. y – 3 = -2x – 8 +2x +2x Then get x on the left. 2x + y – 3 = -8 +3 +3 Then get all constants on the right. 2x + y = -5 You try! Write the standard form of an equation of the line passing through (-5, 1) with a slope of ¾ . y – 1 = ¾ (x + 5) First write in PS form and distribute. 4 [y – 1 = 3 x + 15 ] 4 Then clear the fraction. 4 4 4y – 4 = 3x + 15 -3x -3x -3x + 4y – 4 = 15 +4 +4 -1 [-3x + 4y = 19] -1 3x - 4y = -19 Next get x and y on the left. Then get the constant on the right. Next get the coefficient of x positive. Write the standard form of the equation of… a) b) The horizontal line. Answer: y = 3 The vertical line. Answer: x = -3 . (2, 3) . (-3, -1) You are buying food for a BBQ. Hamburgers cost $2 per pound and chicken costs $3 per pound. You have $60. a) Write an equation that models different amounts of each item you can buy. Let x = lbs of hamburgers bought; Let y = lbs of chicken bought 2x + 5y = 60 b) Model the possible combinations of each item you can buy with a table and a graph. y Chicken lbs. (0, 20) x y 2x + 5y = 60 . 0 20 30 0 2(0) + 5y = 60 10 5 .. (12, 12) (15, 10) 2x + 5(0) = 60 5 10 15 10 2(15) + 5y = 60 12 2(12) + 5y = 60 12 . (30, 0) X lbs. Burgers HW P. 311-312 (19-63 odd, 64-69)