litanalove 92. 1)) тк знаменатель одинаковый, тогда:

=(2a -50) /(√a +5) =

=2(a -25)(√a -5) /(√a +5)(√a -5) =

=2(a -25)(√a -5) /(a -25) =2(√a -5)=2√a -10



2) y -√7 = -(√7 -y)

=(21 -3y²) /(√7 -y) =3(7 -y²)(√7 +y) /(√7 -y)(√7+y)=

=3(7 -y²)(√7 +y) /(7 -y²)=

=3(√7 +y) =3√7 +3y


3) 22√n /11(√a -√b) ×(a -b)/10√n =

=2√n×(a -b) /10√n×(√a -√b) =

=(a -b)(√a +√b) /5(√a -√b)(√a +√b) =

=(a -b)(√a +√b) /5(a -b) =

=(√a +√b)/5


4). =15√d ×(a -c) /30√d×(√ab +√bc) =

=(a -c) /2(√ab +√bc) =

=(a -c)(√ab -√bc) /2(√ab+√bc)(√ab -√bc) =

=(a -c)(√ab -√bc) /2(ab -bc) =

=(a -c)(√ab -√bc) /2b(a -c) =

(√ab -√bc) /2b