Question

Consider the system:

y = 3x + 5
y = ax + b
What values for a and b make the system
inconsistent? What values for a and b make the
system consistent and dependent? Explain.

Answer 1

Explanation:

In this problem, we have the following linear equations:

y=3x+5

y=ax+b

We know that a linear equation is an equation for a line. In a system of linear equations, two or more equations work together.

1. What values for a and b make the system inconsistent?

A system is inconsistent if and only if the lines are parallel in which case the system has no solution. This is illustrated in the first Figure bellow. Two lines are parallel if they share the same slope. So, the system is inconsistent for:

a=3

for any value of b

2. What values for a and b make the system consistent and dependent?

A system is consistent if and only if the lines are the same in which case the system has infinitely many solutions. This is illustrated in the second Figure bellow. So, the system is consistent and dependent for:

a=3 and b=5

Answer 2

When a = 3 and b ≠ 5, the system will be inconsistent because the lines will be parallel. When a = 3 and b = 5, the system will be consistent and dependent because they represent the same line.

Explanation: