Odpowiedzi

Najlepsza Odpowiedź!
2010-03-18T19:57:29+01:00
A) 6.5 - 9x > 0.5(x+1)
zamiana na ulamki
65/10 -9x >5/10x +5/10 /*10 (obustronnie mnożysz przez 10)
65-90x>5x+5
-90x-5x>5-65
-95x>60 /:(-95)
x<-60/95
x< -12-19

b) 0.2(x+2) < 4.4 - x
2/10 x +4/10<44/10 -x /*10
2x+4<44-10x
2x+10x<44-4
12x<40 /:12
x<40/12
x<10/3
x<3 1/3

c) 0.5x > 2(0.1x + 0.25)
5/10 x>2(1/10 x +25/100)
5/10 x >2/10 x +50/100 (przy 50/100 zera sie skroca)
5/10x-2/10x>5/10 /*10
5x-2x>5
3x>5 /:3
x>5/3
x>1 2/3

d) -0.08(10x+5) ≤ 0.1 (x-20) + 0.4
-8/100(10x+5)≤1/10(x-20)+4/10
-8/100*10x+8/100 *5≤1/10x-20*1/10+4/10
-8/10x+4/10≤1/10x-2+4/10 /*10
-8x+4≤x-20+4
-8x-x≤-4-20+4
-9x≤-20 /: (-9)
x≥20/9

e) 0.1x+ 0.01 ≥ 2( 0.01x + 0.02)
1/10x+1/100 ≥2(1/100x+2/100)
1/10x+1/100 ≥2/100x+4/100 /*100
10x+1 ≥2x+4
10x-2x ≥4-1
8x ≥3 /:8
x ≥3/8

f) 5(0.16x - 0.01) < 0.2 (1-x)
5(16/100x-1/100)<2/10(1-x)
80/100x-5/100<2/10-2/10x /*10
8x-50/100<2-2x
8x-0,5<2-2x
8x+2x<2+0,5
10x<2,5 /*10
x<25

prosze o naj troche sie nameczylam;)



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