Question

2x+3y+2z=13 2y+z=1 z=3

Answer 1

Given

z = 3

2y +z = 1

2x +3y +2z = 13

Find

x, y, z

Solution

... z = 3 is given

Substitute that into the second equation.

... 2y + 3 = 1

... 2y = -2 . . . . . subtract 3

... y = -1 . . . . . . . divide by the coefficient of y

Substitute these two solutions into the third equation.

... 2x +3(-1) +2(3) = 13

... 2x = 10 . . . . . . . . . . . .  collect terms, subtract 3

... x = 5 . . . . . . . . . . . . . . divide by the coefficient of x

The variable values are: x = 5, y = -1, z = 3