Question

Proszę jak najszybciej o POMOC ! będe bardzo wdzięczna : D

Answer 1

2.
a) (6a + 7) / 7 - 3 = (5a - 3)/8  | *56
8(6a+7)-168=7(5a-3)
48a+56-168=35a-21
48a-35a=-21+168-56
13a=91  | :13
a = 7

b) (b-4)/3=9-(2b-41)/9    |*9
3(b-4)=81-(2b-41)
3b-12=81-2b+41
5b=110  |:5
b=22



c) 10-(3c-1)/2=(6c+3)/11         |*22
220-11(3c-1)=2(6c+3)
220-33c+11=12c+6
-45c=-181      |:(-45)
c=-4 1/45



d) 2-(3a-7)/4 + (a+17)/5 = 0        |*20
40-5(3a-7)+4(a+17)=0
40-15a+35+4a+68=0
-11a=-143        |:(-11)
a=13


e) (b+6)/2+(5-4b)/3=(8-b)/6    |*6
3(b+6)+2(5-4b)=8-b
3b+18+10-8b=8-b
-4b=-20  |:(-4)
b=5


f) (9c+7-2c)/2+(c-2)/7=36       |*14
7(9c+7-2c)+2(c-2)=504
63c+49-14c+2c-4=504
51c=459  |:81
c=9



ZADANIE 1:
a) 13x-8(3x-2)=-7x-5(12-3x)
13x-24x+16=-7x-60+15x
-19x=-76  |:(-19)
x=4


b) 7(2x-1)-6(11-x)=3(x+4)
14x-7-66+6x=3x+12
17x=85  |:17
x=5


c) (x+5)(x+2)-3(4x-3)=(x-5)^2
x^2+2x+5x+10-12x+9=x^2-10x+25
5x=-6  |:5
x=-1 1/5

d) 12-2(x-1)^2=4(x-2)-(x-3)(2x-5)
12-2(x^2-2x+1)=4x-8-(2x^2-5x-6x+15)
12-2x^2+4x-2=4x-8-2x^2+11x-15
11x=33  |:11
x=3