Question

BŁAGAM POMOCY !!!! NA JTRO MAM ZADANIA Z MATEMATYKI UKŁADY RÓWNAN METODA PRZECIWNYCH WSPOL CZYNNIKOW !!!!

(daje naj kto zrobi wszystkie!!!)

a) 2(x-3)+3(y-5)=4(x_1)-3(y-7)

2(x+y)-5(y-x)=3(2x-y)+5(5x-3y)

b) -3(x-y)+8(2x+y)=3(x+2y)-5(x+y)

-2(x-3)+6(y+4)=3(x+1)-(y+4)

c) 3(2x+y)-5(y-x)=2(3x-2y)+3(x-y)

-5(x+2)+3(y-1)=4(1-2x)-2(9+2y)

d) 2(x+3)-(2y-3)=5(x+2)-4(y-2)

3(3x+y)+4(y-3x)=5(y+x)+2(2y-x)

Answer 1

a)

2(x-3)+3(y-5)=4(x-1)-3(y-7)

2(x+y)-5(y-x)=3(2x-y)+5(5x-3y)

 

2x-6+3y-15=4x-4-3y+21

2x+2y-5y+5x=6x-3y+25x-15y

 

2x+3y-4x+3y=-4+21+6+15

2x+2y-5y+5x-6x+3y-25x+15y=0

 

-2x+6y=38/*(-12)

-24x+15y=0

 

24x-72y=-456

-24x+15y=0

----------------------

-57y=-456

y=8

 

-2x+6y=38

-2x+6*8=38

-2x+48=38/-48

-2x=-10/:(-2)

x=5

b)

-3(x-y)+8(2x+y)=3(x+2y)-5(x+y)

-2(x-3)+6(y+4)=3(x+1)-(y+4)

 

-3x+3y+16x+8y=3x+6y-5x-5y

-2x+6+6y+24=3x+3-y-4

 

-3x+3y+16x+8y-3x-6y+5x+5y=0

-2x+6y-3x+y=3-4-6-24

 

15x+10y=0

-5x+7y=-31/*3

 

15x+10y=0

-15x+21y=-93

----------------------

31y=-93/:31

y=-3

 

15x+10y=0

15x+10*(-3)=0

15x-30=0/+30

15x=30/:15

x=2

c)

3(2x+y)-5(y-x)=2(3x-2y)+3(x-y)

-5(x+2)+3(y-1)=4(1-2x)-2(9+2y)

 

6x+3y-5y+5x=6x-4y+3x-3y

-5x-10+3y-3=4-8x-18-4y

 

6x+3y-5y+5x-6x+4y-3x+3y=0

-5x+3y+8x+4y=4-18+10+3

 

2x+5y=0/*(-3)

3x+7y=-1/*2

 

-6x-15y=0

6x+14y=-2

-------------------

-y=-2/*(-1)

y=2

 

2x+5y=0

2x+5*2=0

2x+10=0

2x=-10/:2

x=-5

 

d)

2(x+3)-(2y-3)=5(x+2)-4(y-2)

3(3x+y)+4(y-3x)=5(y+x)+2(2y-x)

 

2x+6-2y+3=5x+10-4y+8

9x+3y+4y-12x=5y+5x+4y-2x

 

2x-2y-5x+4y=10+8-6-3

9x+3y+4y-12x-5y-5x-4y+2x=0

 

-3x+2y=9

-6x-2y=0

---------------

-9x=9/:(-9)

x=-1

 

-6x-2y=0

-6*(-1)-2y=0

6-2y=0

-2y=-6/:(-2)

y=3