(a) Evaluate and express your answer in standard form : (frac{4.56 times 3.6}{0.12})
(b) Without using mathematical tables or calculator, evaluate ((73.8)^{2} – (26.2)^{2}).
(c) Simplify (sqrt{1frac{19}{81}}), expressing your answer in the form (frac{a}{b}) where a and b are positive integers.
Explanation
(a) (frac{4.56 times 3.6}{0.12} equiv frac{4.56 times 360}{12})
= (4.56 times 30 )
= (136.8 )
= (1.368 times 10^{2})
(b) ((73.8)^{2} – (26.2)^{2})
Using the method of difference of two squares,
= ((73.8 + 26.2) times (73.8 – 26.2))
= (100 times 47.6)
= (4760)
(c) (sqrt{1frac{19}{81}})
= (sqrt{frac{100}{81}})
= (frac{10}{9})