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BogdanCris
a fost răspuns

20. (a,b). Dau coroana​

20 Ab Dau Coroana class=

Răspuns :

Răspuns:

a. 10x-5+3x-3-42x+72=120-15x-84

10x+3x-42x+15x=120-84+5+3-72

-14x=-28

x=28:14

x=2

b. 6x+8-3x-2=12x-18+6-8x+10x-15

6x-3x-12x+8x-10x=-18+6-15-8+2

-11x=-33

x=33:11

x=3

Răspuns:

[tex]\bf \red{a)~~x=2}[/tex]

[tex]\bf \blue{b)~~x=3}[/tex]

Explicație pas cu pas:

[tex]\bf a)~5(2x-1)+3(x-1)-6(7x-12)=15(8-x)-84[/tex]

[tex]\bf 10x-5+3x-3-42x+72=120-15x-84[/tex]

[tex]\bf 10x+3x-42x+64=36-15x[/tex]

[tex]\bf 10x+3x-42x+15x=36-64[/tex]

[tex]\bf -14x=-28~~~~\bigg|:(-14)[/tex]

[tex]\bf \red{\underline{x=2}}[/tex]

[tex]\bf b)~~2(3x+4)-3x-2=6(2x-3)+2(3-4x)+5(2x-3)[/tex]

[tex]\bf 6x+8-3x-2=12x-18+6-8x+10x-15[/tex]

[tex]\bf 3x+6=14x-27[/tex]

[tex]\bf 3x+6+27=14x[/tex]

[tex]\bf 3x+33=14x[/tex]

[tex]\bf 33=14x-3x[/tex]

[tex]\bf 33=11x[/tex]

[tex]\bf x = 33:11[/tex]

[tex]\bf \blue{\underline{x=3}}[/tex]

==pav38==