d)
[tex](3 \frac{1}{2} - 2 \frac{1}{3} ) \div \frac{5}{6} = \\ ( \frac{7}{2} - \frac{7}{3} ) \times \frac{6}{5} = \\ \frac{7}{6} \times \frac{6}{5} = \\ 7 \times \frac{1}{5} = \frac{7}{5} [/tex]
e)
[tex]( \frac{1}{2} )^{ - 2} \times ( \frac{3}{4} ) + (- 2) ^{3} - ( \frac{5}{2} - 3) = \\ {2}^{2} \times \frac{3}{ {2}^{2} } - 8 - ( - \frac{1}{2} ) = \\ 3 - 8 + \frac{1}{2} = \\ - 5 + \frac{1}{2} = \\ - \frac{9}{2} [/tex]
2.
a)
[tex] \frac{2}{3} x + 2 = \frac{5}{3} \: \: inmultim \: ambele \: parti \\ \: ale \: ecuatiei \: cu \: 3 \\ = > 2x + 6 = 5 \\ 2x = 5 - 6 \\ 2x = - 1 \\ x = - \frac{1}{2} [/tex]
b)
[tex] \frac{2x - 1}{6} - \frac{x - 2}{3} = \frac{x + 2}{4} \: inmultim \: \\ ambele \: parti \: ale \: ecuatiei \: cu \: 12 \\ = > 2(2x - 1) - 4(x - 2) = 3(x + 2) \\ 4x - 2 - 4x +8 = 3x + 6 \\ 6 = 3x + 6 \\ 3x = 0 \\ x = 0[/tex]
3.
a)
[tex] \frac{5}{a} = \frac{b}{3} \\ a \times b = 5 \times 3 \\ 5 \times 3 = 15 \: (produsul \: mezilor)[/tex]
(avand in vedere ca a×b=5×3 => a×b=15)
