Finding the Unknown — Question 13

(i) u = 6 Multiply both sides by \(\frac {2}{3}\) ⇒ \(\frac {2}{3}\)u = \(\frac {2}{3}\) × 6 ⇒ \(\frac {2}{3}\)u = 4 (ii) u = 6 Add 7 to both sides u + 7 = 6 + 7 ⇒ u + 1 = 13 (iii) u = 6 Multiply both sides by 2 2u = 12 Add 3 to both sides ⇒ 2u + 3 = 12 + 3 ⇒ 2u + 3 = 15 (iv) u = 6 Multiply both sides by 3 3u = 18 Subtract 5 from both sides 3u – 5 = 18 – 5 ⇒ 3u – 5 = 13