14/5=2,8дм - ширина прямоугольника
2,8*100/5=56%
Ответ: 56%
1) ( 2/15 ) + ( 7/12 ) = ( 8/60 ) + ( 35/60 ) = 43/60
2) ( 43/60 ) * ( 30/43 ) = 30/60 = 1/2
3) 2 : 2 ( 1/2 ) * ( 5/32 ) = 2 : ( 5/2 ) * ( 5/32 ) = ( 4/5 ) * ( 5/32 ) = 1/8
4) ( 1/2 ) - ( 1/8 ) = ( 4/8 ) - ( 1/8 ) = 3/8
Ответ 3/8
8y-3(2y-3)=7y-2(5y+8)
8y-6y+9=7y-10y-16
8y-6y-7y+10y=-9-16
5y=-25
y=-25:5
y=-5
Жауабы:y=-5
2) 5(2y-9)+6y=4(3y-2)-21
10y-45+6y=12y-8-21
10y+6y-12y=45-8-21
4y=16
y=16:4
y=4
Жауабы:y=4
3) 5y+7(3-y)=3(5-2y)-6
5y+21-7y=15-6y-6
5y-7y+6y=-21+15-6
4y=-12
y=12:4
y=3
Жауабы:y=3
4)7y-4(3y+5)=2-3(4y-9)
7y-12y-20=2-12y+27
7y-12y+12y=20+2+27
7y=49
y=49:7
y=7
Жауабы:y=7
А = { 2 ;4 ; 5 ; 7 }
В = { 1 ; 2 ; 3 ; 5 ; 7 }
1) А ∩ В = { 2 ; 5 ; 7 }
2) А ∪ В = { 1 ; 2 ; 3 ; 4 ; 5 ;7 }