6)Notam prețul inițial cu x
[tex]x - \frac{25}{100} {}^{(5} \times x = 750 \\ \\ x - \frac{1}{4} x = 750 \\ \\ 1x - 0.25x = 750 \\ \\ 0.75x = 750 \\ \\ x = 750 \div 0.75 \\ \\ x = \frac{750}{1} \div \frac{75}{100} \\ \\ x = \frac{750}{1} \times \frac{100}{75} \\ \\ x = \frac{75000}{75} \\ \\ x = 1000 \: lei[/tex]
7)
[tex]100 + \frac{10}{100} \times 100 = \\ \\ = 10 + \frac{1000}{100} = \\ \\ = 100 + 10 = 110 \: lei[/tex]
8)
[tex]x - \frac{30}{100} \times x = 700 \\ \\ 1 x - 0.3x = 700 \\ \\ 0.7x = 700 \\ \\ x = 700 \div 0.7 \\ \\ x = \frac{700}{1} \div \frac{7}{10} \\ \\ x = \frac{700}{1} \times \frac{10}{7} \\ \\ x = \frac{7000}{7} \\ \\ x = 1000 \: lei[/tex]
9)
[tex]x - \frac{10}{100} \times x = 90 \\ ............[/tex]
rezolvă ecuația
10)
[tex]x - \frac{10}{100} \times x = 99 \\............... [/tex]
rezolvă ecuația
11)
[tex]150 + \frac{30}{100} \times 150 = \\ = 150 + \frac{30 \times 150}{100} = \\ \\ = 150 + 3 \times 15 = \\ \\ = 150 + 45 = \\ \\ = 195 \: lei[/tex]
12)
[tex]120 + \frac{10}{100} \times 120 = \\ \\ = 120 + \frac{1200}{100} = \\ \\ = 120 + 12 = 132 \: lei[/tex]
