4(х-3z) +33z=50

5(x+2z) -3x=18

4x-12z+33z=50

5x+10z-3x=18

4x+21z=50

2x+10z=18

4x+21z=50

2x=18-10z

4x+21x=50

x=18-10z/2(винесемо спільнота дужки)

x=2(9-5z) /2(скорочуемо 2)

x=9-5z

4(9-5z) +21z=50

x=9-5z

35-20z=50

x=9-5z

-20z=15

z=-0.75 или 3/4

z=-0.75

x=9-5*(-0.75)

z=-0.75

x=9+3.75

z=-0.75

x=12.75

4x+7=5(x-t)

3(x+6t)-9t=15

4x+7=5x-5t

3x+18t-9t=15

-x+5t=-7

3x+9t=15

-x=-7-5t

3x+9t=15

x=5t+7

3(5t+7)+9t=15

x=5t+7

15t+21+9t=15

x=5t+7

24t=-6

x=5t+7

t=-0.25

x=-1.25+7

t=-0.25

x=5.75

t=-0.25