4.a)
[tex]7\%din 50 = \frac{7}{100} \times 50 = \frac{7 \times 50}{100} = \frac{350}{100} [/tex]
[tex] \frac{350}{100} = 3.5[/tex]
b)
[tex]2\%dinx = 20 < = > \frac{2x}{100} = 20 [/tex]
[tex] \frac{2x}{100} = 20 < = > 2x = 200 < = > x = 100[/tex]
[tex]x = 100[/tex]
5.
[tex]5\%din40 = \frac{5}{100} \times 40 = \frac{200}{100} = 2[/tex]