А) х=12; у=17
Б) х=-7; у=-10
С) у=12; х=11
Д) х=2 ; у= 13
Е) x=3/2; y=-1/2
Пошаговое объяснение:
А) 2*(х-5)=у-3
х+5=у
2(х-5)=х+5-3; 12+5=у
х=12
у=17
ответ : х=12; у=17
Б) 3*(х – у) = 9
2*х = у – 4
3(x-y)=9
y=4+2x
3(x-(4+2x))=9; y=4+2(-7)
x=-7
y=-10
ответ: х=-7; у=-10
С) 3*(у – 6) – 2*(4 – х ) = 12
4Х + 2у + 4 = 11
3(y-6)-8+6x=12
y=7/2-2x
3(7/2-2x-6) - 2(4-x)=12
x=-55/8
y=7/2-2(-55/8)
y=69/4
ответ: у=12; х=11
Д) х + у – 10 = 5
у – х = 11
x+y=15
-x+y=11
2y=26 ; -x+13=11
y=13
x=2
ответ: х=2 ; у= 13
Е) 3х – 5 = у
Х + 2 = у
3x-y=5
x-y=2
2x=3
ответ : x=3/2; y=-1/2
1) 7 7/9 - 4 1/12 = 7 28/36 - 4 3/36 = 3 25/36
2) 3 25/36 + 2 3/4 = 3 25/36 + 2 27/36 = 5 + 52/36=
= 5+ 13/9 = 5 + 1 4/9 = 6 4/9
17 2/3 - 6 1/36 + 4 3/8 = 16 1/72
1) 17 2/3 - 6 1/36 = 17 24/36 - 6 1/36 = 11 23/36
2) 11 23/36 + 4 3/8 = 11 46/72 + 4 27/72 = 15 + 73/72=
=15 + 1 1/72 = 16 1/72
10 9/16 - (3 11/12 + 4 4/9 ) = 2 29/144
1) 3 11/12 + 4 4/9 = 3 33/36 + 4 16/36 = 7 + 49/36=
= 7 + 1 13/36 = 8 13/36
2)10 9/16 - 8 13 /36 = 10 81/144 - 8 52/144 = 2 29/144
(20 - 7 23/36) - (14 4/27 - 6 1/18) = 4 29/108
1) 20 - 7 23/36 = 12 13/36
2) 14 4/27 - 6 1/18 = 14 8/54 - 6 3/54 = 8 5/54
3) 12 13/36 - 8 5/54 = 12 39/108 - 8 10/108= 4 29/108