Question

Rozwiąż układ równań metodą podstawiania

16x-27y=-6

5x-18y=-21

Answer 1

16x-27y=-6

5x-18y=-21

 

16x=-6+27y   //:16

x=1/16(-6+27y)

 

5x-18y=-21

5(1/16(-6+27y))-18y=-21

5(-6/16+27/16y)-18y=-21

-30/16+135/16y-18y=-21

135/16y-288/16y=-21+30/16

-153/16y = -336/16+30/16

-153/16y = -306/16   //* (-16/153)

y = 4896/2448

y = 2

 

5x-18y=-21

5x-18*2=-21

 

5x=-21+36

5x=1

 x=3

 

 spr:

16x-27y=-6

5x-18y=-21

 

16*3-27*2=-6

5*3-18*2=-21

 

48-54=-6

15-36=-21

 

-6=-6

-21=21

Answer 2

16x=-6 + 27y / : 16

x=-6 +27y/16

 

5 * (-6+27y/16) - 18y = -21

-30 + 135y/16 -18y = -21 / *16

-30 + 135y - 288y = -336

-153y = -306 / ; (-153)

y = 2

 

x=-6 + 27 * 2 /16

x= 3