Odpowiedzi

2010-04-14T11:48:23+02:00
A.
7x+4 /5 - x=3x-5/2 /*10
2(7x+4)-10x=5(3x-5)
14x+8-10x=15x-25
4x-15x=-25-8
-11x=-33 /:(-11)
x=3

B.
9-7x/3 +1 ≤ x -1-x/2 /*6
2(9-7x)+6 ≤ 6x - 3(1-x)
18-14x+6 ≤ 6x- 3-3x
-14x-3x ≤ -24-3
-17x ≤ -27 /:(-17)
x ≥ 1¹⁰/₁₇