Detrerminati numarul necunoscut din fiecare proportie:
a) x-2supra 5=2x-1 supra 13.
b) 2x+3 supra x+5=7 supra 4.
c) 4x-5 supra 3=2x+8 supra 2.
d) 3x+11 supra 9=x+6 supra 4.
e) 4 supra 9=3x+1 supra 2x+12.
f)3 supra 5x+2=7 supra 2x+15.


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Răspunsuri

2014-08-22T22:32:54+03:00
A)13(x-2)=5(2x-1)
13x-26=10x-5
13x-10x=-5+26
3x=21
x=21/3
x=7
b)4(2x+3)=7(x+5)
8x+12=7x+35
8x-7x=35-12
x=23
c)2(4x-5)=3(2x+8)
8x-10=6x+24
8x-6x=24+10
2x=34
x=34/2
x=17
d)4(3x+11)=9(x+6)
12x+44=9x+54
12x-9x=54-44
3x=10
x=3/10
e)4(2x+12)=9(3x+1)
8x+48=27x+9
8x-27x=9-48
-19x=-39
x=19/39
f)3(2x+15)=7(5x+2)
6x+45=35x+14
6x-14x=14-45
-8x=-31
x=8/31
5 4 5