1) 751-387-551+387-600 = (751-551) + (387-387) -600=200-600=-400
2) (4,7-4,9)+(4,9-5,1)-(-5,1-5,3) = 4,7-4,9+4,9-5,1+5,1+5,3=(-4,9+4,9)+(5,1-5,1)+(5,3+4,7)=10
3) 4,6*7,3+5,4*8,5+4,6*8,5+5,4*7,3 = 7,3*(4,6+5,4)+8,5*(5,4+4,6)=7,3*10+8,5*10=73+85=158
4) 9,8*17,42+9,8*5,58-1,8*17,42-1,8*5,58= 9,8*(17,42+5,58)-1,8*(17,42+5,58)=9,8*23-1,8*23=23*(9,8-1,8)=23*8=184
5) 15,37*7,88-9,37*7,88+15,37*2,12-9,37*2,12= 15,37*(7,88+2,12)-9,37*(7,88+2,12)=15,37*10-9,37*10=153,7-93,7=60
6) 4,54*77,7-4,54*7,7+7,46*77,7-7,46*7,7= 77,7*(4,54+7,46)-7,7*(4,54+7,46)=77,7*12-7,7*12=12*(77,7-7,7)=12*70=840
7) 75,9*42,3-65,9*42,3+628*1,77-528*1,77= 42,3*(75,9-65,9)+1,77*(628-528)=42,3*10+1,77*100=423+177=600
№1а) y=2x4x+5y=284x+10x=2814x=28x=2y=2*2=4(2;4)б) 2u-v=3 = > v=2u-3 7u+3v=47u+6u-9=413u=13u=1v=2-3=-1(1;-1)в) p-3q=1 => p=3q+1p^2-9q=7(p-3q)(p+3q)=71*(p+3q)=7p+3q=73q+1+3q=76q=6q=1p=3+1=4(4;1)г) x=2zy-z+3=0 => y=z-3x+y+z=92z+z-3+z=94z=12z=3y=3-3=0x=3*2=6(6;0;3)№2а) a=3b5a+2b=3415b+2b=3417b=34b=2a=3*2=6(6;2)б) 3p-q=2 => q=3p-25p-3q=-65p-9p+6=-64p=12p=3q=9-2=7(3;7)в) u-2q=1 =>u=2q+1u^2-4q=5(u-2q)(u+2q)=51*(u+2q)=5u+2q=5 2q+1+2q=54q=4q=1u=2+1=3(3;1)г) z=4xy-x-2=0 => y=x+2x+2y-z=3 x+2x+4-4x=3x=1z=4y=1+2=3
(1;3;4)
1) 751-387-551+387-600 = (751-551) + (387-387) -600=200-600=-400
2) (4,7-4,9)+(4,9-5,1)-(-5,1-5,3) = 4,7-4,9+4,9-5,1+5,1+5,3=(-4,9+4,9)+(5,1-5,1)+(5,3+4,7)=10
3) 4,6*7,3+5,4*8,5+4,6*8,5+5,4*7,3 = 7,3*(4,6+5,4)+8,5*(5,4+4,6)=7,3*10+8,5*10=73+85=158
4) 9,8*17,42+9,8*5,58-1,8*17,42-1,8*5,58= 9,8*(17,42+5,58)-1,8*(17,42+5,58)=9,8*23-1,8*23=23*(9,8-1,8)=23*8=184
5) 15,37*7,88-9,37*7,88+15,37*2,12-9,37*2,12= 15,37*(7,88+2,12)-9,37*(7,88+2,12)=15,37*10-9,37*10=153,7-93,7=60
6) 4,54*77,7-4,54*7,7+7,46*77,7-7,46*7,7= 77,7*(4,54+7,46)-7,7*(4,54+7,46)=77,7*12-7,7*12=12*(77,7-7,7)=12*70=840
7) 75,9*42,3-65,9*42,3+628*1,77-528*1,77= 42,3*(75,9-65,9)+1,77*(628-528)=42,3*10+1,77*100=423+177=600
№1
а) y=2x
4x+5y=28
4x+10x=28
14x=28
x=2
y=2*2=4
(2;4)
б) 2u-v=3 = > v=2u-3
7u+3v=4
7u+6u-9=4
13u=13
u=1
v=2-3=-1
(1;-1)
в) p-3q=1 => p=3q+1
p^2-9q=7
(p-3q)(p+3q)=7
1*(p+3q)=7
p+3q=7
3q+1+3q=7
6q=6
q=1
p=3+1=4
(4;1)
г) x=2z
y-z+3=0 => y=z-3
x+y+z=9
2z+z-3+z=9
4z=12
z=3
y=3-3=0
x=3*2=6
(6;0;3)
№2
а) a=3b
5a+2b=34
15b+2b=34
17b=34
b=2
a=3*2=6
(6;2)
б) 3p-q=2 => q=3p-2
5p-3q=-6
5p-9p+6=-6
4p=12
p=3
q=9-2=7
(3;7)
в) u-2q=1 =>u=2q+1
u^2-4q=5
(u-2q)(u+2q)=5
1*(u+2q)=5
u+2q=5
2q+1+2q=5
4q=4
q=1
u=2+1=3
(3;1)
г) z=4x
y-x-2=0 => y=x+2
x+2y-z=3
x+2x+4-4x=3
x=1
z=4
y=1+2=3
(1;3;4)