Rational Numbers & Equations Lesson 3-5
Rational Numbers & Equations When given an equation with a fraction… a)Solve by multiplying by the reciprocal b)Solve by canceling fractions using the LCD (lowest common denominator)
Solving by a fraction To “solve” with a fraction multiply by the reciprocal 2 m = m = m = m = 300 given Multiply by reciprocal [Check for cross reducing] (Fractions cancelled out) Solve!
Solving by a fraction 2 y = y = y = 4 5 y = 20 - b = b = b = 2 -8 b = -16
Solving a fraction equation To “solve” with fractions in the problem multiply all terms by the LCD 1 x + 3 x = (4) 1 x + (4) 3 x = 5 (4) 2 4 2x + 3x = 20 5x = 20 x = 4 given Multiply all equation terms by LCD [Cross reduce to cancel denominators] New equation Solve!
Solving a fraction equation y + y = (24) 2y + (24) 3y = -4 (24) y + 6y = y = -96 y = -8
Practice… Solve… a)_ 3 f = 6 4 b)-2 = 4c 9 c) 2y + y = d) 3n – 2 = -7 5
Homework p. 131 #14-17, 19-22, 31-33