Question

1,2,3.Dau coroana.multumesc!

Answer 1

1.a+b=110=>a=110-b
ax80/100-bx20/100=78
4a/5-b/5=78
Inmultim,ecuatia,cu,5
4a-5b=390
4(110-b)-5b=390
440-4b-b=390
-5b=390-440
-5b=-50=>b=10=>a=100

2.(√2x+3)/3-x/√2+6x/√18=(18-√2x)/6
Rationalizam,intai,numitorii,si,scriem,√18=3√2
(√2x+3)/3-√2x/2+6√2x/6=(18-√2x)/6
Aducem,la,numitor,comun(6)
2√2x+6-3√2x+6√2x=18-√2x
6√2x=12=>x=12/6√2=>x=√2