Theory question 101
Fractions, Decimals and Approximation(a) Simplify: (4 2/9 − 1 13/15) / (2 1/5 + 4/7 × 2 1/3)
(b) By rationalizing the denominator, simplify: 7√5/√7 (Leave your answer in surd form)
Show the model answer
Model answer
(a) Numerator: 38/9 − 28/15 = (190 − 84)/45 = 106/45.
Denominator: do the multiplication first: 4/7 × 7/3 = 4/3; 11/5 + 4/3 = 53/15.
106/45 ÷ 53/15 = 106/45 × 15/53 = 2/3.
(b) 7√5/√7 × √7/√7 = 7√35/7 = √35.
Explanation
Change mixed numbers to improper fractions and do × before + in the denominator.