INTRO TO ALGEBRA: The “term” The basic unit of algebra is a “term”. 6a -xy 4b2 Nelson Marlborough Institute of Technology TE WHARE WANANGA O TE TAU IHU -0.7p It has 3 parts: 1. a sign, being positive (+) or negative (-) 2. a number, called ‘the coefficient’ 3. a letter, called ‘the variable’ Every term must have a sign. If there isn’t one, assume there is an unwritten positive sign. Negative signs must always be written. Terms must have a number. If there isn’t one, assume an unwritten coefficient of ‘one’. Terms may or may not have a letter. If there is a variable and it has a power above the variable (eg. 7x3), the power belongs only to the variable. Practise with the following terms: Sign (+ or -) Example 8f -10r 4xy ½m -22 Coefficient Variable(s) When several basic algebraic units, or terms, are written one after the other, the sign separates one term from the one before it. Remember that the sign belongs with the term to its immediate RIGHT. Put a circle around each term in the following algebraic expressions: 10b – 42de + km m2n – a – c -p3 + 16 – ¼ qr -9y + 3b – 5 Library Learning Centre LEARNING SUPPORT Updated 6/02/2016 INTRO TO ALGEBRA: The “term” Nelson Marlborough Institute of Technology TE WHARE WANANGA O TE TAU IHU Adding and subtracting in Algebra This is also referred to as “simplifying terms” or “combining like terms”. You can only simplify terms with the same variables (meaning, same letters). B+B 2a + 3a 6y + 8ab 9G2 + 1G really means 1B + 1B,so the answer is 2B the answer is 5 variables called ‘a’ since the letters are all different, no simplification! B + B = 2B 2a + 3a = 5a 6y + 8ab 9G2 + 1G since only one variable has a power, no simplification! It is just like adding things in real life. 4 coffees + 3 teas = 4 coffees + 3 teas 4c + 3t = 4c + 3t 4 drinks + 3 drinks = 7 drinks 4d + 3d = 7d we can’t combine them simplify, same variables If any terms are negative, visualise a number line. Start at zero and then count to your first term, by moving to the right for positive terms and to the left for negative terms. For the next term, count from this new position and move right or left depending on the sign of the next term. Example: - 4z + 1z Using a number line, -5 -4 -3 -2 -1 0 1 2 Start at zero and count four to the LEFT: -5 -4 -3 -2 -1 0 1 2 1 2 From –4 count one to the RIGHT: -5 -4 -3 -2 -1 0 The answer is -3z. Practise: 1. –2x + 4x 2. 3b – 7b + b 3. p + 2q + 3p – 3q 4. 9zy + 3zy 5. 12w + 2wz – 2w 6. 3x2 + 1x – 4x2 7. 6s + s3 + 7s2 Library Learning Centre LEARNING SUPPORT Updated 6/02/2016