1)(3,6xy+2,1y²)/(1,44x²-0,49y²)+2x/(2,4x+1,4y)=
=3y(1,2x+0,7y)/(1,2x-0,7y)(1,2x+0,7y) +2x/2(1,2x+0,7y)=
=3y/(1,2x-0,7y) +x/(1,2x+0,7y)=(3,6xy+2,1y²+1,2x²-0,7xy)/(1,2x-0,7y)(1,2x+0,7y)=
=(1,2x²+2,1y²+2,9xy)/(1,2x-0,7y)(1,2x+0,7y)
2)(1,2x²+2,1y²+2,9xy)/(1,2x-0,7y)(1,2x+0,7y) *10x(1,2x+0,7y)/(x+3y)=
=10x(1,2x²+2,1y²+2,9xy)/(1,2x-0,7y)(x+3y)