a)

5(2 – 3x) = 1 – (7 – x)

10 – 15x = 1 – 7 + x

10 – 15x =  –6 + x

–15x – x = –6 – 10

– 16x = –16   /: (–16)

x = 1

Sprawdzenie:

L = 5(2 – 3x) = 5(2 – 3 · 1) = 5 · (2 – 3) = 5 · (–1) = - 5

P = 1 – (7 – x) = 1 – (7 – 1) = 1 – 6 = –5

L = P   

b)

3x – (1 – x) = –2(4 –