Question

Calculati ecuatiile x £ Z
a) 2(2x+1)-4(x+3)=5-3(2x+1)
b) 3x+5-2(x+2)=8-3(1-x)
c) 19-4(3x-8)=3
d) 3(2x-7)-5(3x+1)+4x=8-2(5x-3)

Answer 1

a) 2x+2-4x-12=5-6x-3=>2x-4x+6x=-2+12+5-3=>4x=12=>x=3
b)3x+5-2x-4=8-3+3x=>3x-2x-3x=-5+4+8-3=>-2x=10 |(-1)=>2x=-10=>x=-5
c)19-12x+32=3=>-12x=-19-32+3=>-12x=-48 |(-1)=>12x=48=>x=4
d)6x-21-15x-5+4x=8-10x+6=>-6x+15x-4x-10x=21+5+8+6=>-5x=40=>|(-1)=>5x=40=>x=8. sunt sigur ca sunt bine facute.