2b- 4b²/b-3= 2) x+4y/15 +4x+y/15=

(2b-4b^2)/(b-3)=(2b(1-2b)) /(b-3) (x+4y)/15 +(4х+у)/15=(х+4у+4х+у)/15=(5(х+у))/15=(х+у)/3