Question

Use back-substitution to solve the system of linear equations.

Answer 1

Step-by-step explanation:

x - y + 5z = 29

y + 2z = 4

z = 7

since z = 7 we can use this value in second equation

y + 2×7 = 4 and y = -10

now we know the value of y we can solve the first equation

x -(-10) + 5×7 = 29

x + 10 + 35 = 29

x = -11

Answer 2

Answer:

work is shown and pictured