8) 9) 10) 11) 12) 13) 14) Chapter 5: CHANGING THE SUBJECT OF A FORMULA We can use algebra to change the subject of a formula. Rearranging a formula is similar to solving an equation we must do the same to both sides in order to keep the equation balanced. – Example 1: Make the subject of the formula = 4x + 3. x y Solution: = 4x + 3 y Subtract 3 from both sides: 3 = 4x y – Divide both sides by 4; So is the same equation but with the subject. x Example 2: Make the subject of = 2 5x x y – Solution: Notice that in this formula the term is negative. x
8) 9) 10) 11) 12) 13) 14) Chapter 5: CHANGING THE SUBJECT OF A FORMULA We can use algebra to change the subject of a formula. Rearranging a formula is similar to solving an equation – we must do the same to both sides in order to keep the equation balanced. Example 1: Make x the subject of the formula y = 4x + 3. Solution: y = 4x + 3 Subtract 3 from both sides: y – 3 = 4x Divide both sides by 4; So is the same equation but with x the subject. Example 2: Make x the subject of y = 2 – 5x Solution: Notice that in this formula the x term is negative.