1) x+2a-2b=8=> x+2(a-b)=8
a-b=4
=> x+ 2*4=8
=> x+8=8
=> x=0
2) x+1=30+5a- 5b=> x+1=30+5(a-b)
a-b=4
=> x+1= 30+5*4
=> x+1= 30+20
=> x+1= 50 \-1
=> x=49
3)5a-5b-x=10=> 5(a-b)-x=10
a-b=4
=> 5*4-x=10
=> 20-x=10
=> x=20-10
=> x=10
4)x+16+8a-8b=49=> x+16+8(a- -b)=49
a-b=4
=> x+16+8*4=49
=> x+16+32=49
=> x+48=49\-48
=> x=1
sper ca te-am ajutat!
