Cześć!
Szczegółowe wyjaśnienie:
a)
[tex]2x = - 30 \\ 2x \div 2 = - 30 \div 2 \\ x = - 15[/tex]
b)
[tex] - 4.5x = - 90 = \\ - 4.5x \div ( - 4.5) = - 90 \div ( - 4.5) \\ x = 20[/tex]
c)
[tex] \frac{3}{4} x = 15 = \frac{4}{3} \cdot \frac{3}{4} x = \frac{4}{3} \cdot15 \\ x = 4 \cdot5 = 20[/tex]
d)
[tex]0.2x = 6 \\ 0.2x \div 0.2 = 6 \div 0.2 \\ x = 30[/tex]
e)
[tex]8 - x = 19 \\ - x = 19 - 8 \\ - x = 11 \\ x = - 11[/tex]
f)
[tex]x + 19 = 28 = \\ x = 28 - 19 \\ x = 9[/tex]
g)
[tex]16a - (4a - 5) = 20 \\ 16a - 4a + 5 = 20 \\ 12a + 5 = 20 \\ 12a = 20 - 5 \\ 12a = 15 \\ a = \frac{5}{4} [/tex]
h)
[tex]5(y - 4) = 10 \\ y - 4 = 2 \\ y = 2 + 4 \\ y = 6[/tex]
