Cześć!
Szczegółowe wyjaśnienie:
a)
[tex]4x = 20 \\ 4x \div 4 = 20 \div 4 \\ x = 5[/tex]
b)
[tex] \frac{2}{3} x = 9 \\ \frac{3}{2} x \cdot \frac{2}{3} x = \frac{3}{2} \cdot9 = \\ x = \frac{27}{2} [/tex]
c)
[tex] - 3x= 8 \\ - 3x\div ( - 3) = 8 \div ( - 3) \\ x = - \frac{8 }{3} [/tex]
d)
[tex]3x + 4 = 13 \\ 3x = 13 - 4 \\ 3x = 9 \div 3 \\ x = 3[/tex]
e)
[tex]5x - 4 = 6 \\ 5x = 6 + 4 \\ 5x = 10 \div 2 \\ x = 2[/tex]
f)
[tex]3(x + 5) = 21 = \\ x + 5 = 7 \\ x = 7 - 5 \\ x = 2[/tex]
g)
[tex]4(x -1 ) = 16 \\ x - 1 = 4 \\ x = 4 + 1 \\ x = 5[/tex]
h)
[tex]3x + 4 = 2x + 7 \\ 3x - 2x = 7 - 4 \\ x = 3[/tex]
i)
[tex]5x - 2 = 3x + 4 \\ 5x - 3x = 4 + 2 \\ 2x = 6 \div 2 \\ x = 3[/tex]
j)
[tex]2(x + 1) + 3(x + 2) = 4 \\ 2x + 2 + 3x + 6 = 4 \\ 5x + 8 = 4 \\ 5x = 4 - 8 \\ 5x = - 4 \div 5 \\ x = - \frac{4}{5} [/tex]
