2р-(3р-2р+с)=
=2р-3р+2р-с=
=1р-с
4
2х(3х-1)=0
2х=0 3х-1=0
х=0/2 3х=1
х=0 х=1/3
х=1
3
9-2(3-4х)-х=-3
9-6+8х-х=-3
3+7х=-3
7х=-6
х=-7\6
B²/(4a-7b)(4a+7b) * (4a-7b)/b =b²*(4a-7b) /(4a-7b)(4a+7b)*b =b/(4a +7b) =8/9 :(8/3 +56/9) =8/9 : (24+56)/9 =8/9 : 80/9 =8/9 * 9/80 =8*9/9*80 =8/80 =1/10 =0.1