Question

20. (a,b). Dau coroana​

Answer 1

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

Answer 2

Răspuns:

$\bf \red{a)~~x=2}$

$\bf \blue{b)~~x=3}$

Explicație pas cu pas:

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

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

$\bf 10x+3x-42x+64=36-15x$

$\bf 10x+3x-42x+15x=36-64$

$\bf -14x=-28~~~~\bigg|:(-14)$

$\bf \red{\underline{x=2}}$

$\bf b)~~2(3x+4)-3x-2=6(2x-3)+2(3-4x)+5(2x-3)$

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

$\bf 3x+6=14x-27$

$\bf 3x+6+27=14x$

$\bf 3x+33=14x$

$\bf 33=14x-3x$

$\bf 33=11x$

$\bf x = 33:11$

$\bf \blue{\underline{x=3}}$

==pav38==