$\"\"$

The line equations are Line a: $\"\"$ , Line b: $\"\"$ ,and Line c: $\"\"$ .

The above three line equations are adjusted in the slope - intercept form of equation or $\"\"$ where m is slope and b is y - intercept.

Therefore slopes of line a, line b and line c are $\"\"$ respectively.

Line c has a slope of $\"\"$ , the negative reciprocal of $\"\"$ , so it is perpendicular to lines c and b. $\"\"$

The lines c and b are perpendicular.