A plumber charges $90 per hour and a $50 travel fee. The total cost of his last job was $410. Use the equation 90x + 50 = 410 to find x, the number of hours it took to complete the job.
To solve this equation, we need to isolate the variable x.
Starting with the equation 90x + 50 = 410:
Subtract 50 from both sides of the equation:
90x + 50 - 50 = 410 - 50
90x = 360
Next, divide both sides of the equation by 90:
90x/90 = 360/90
x = 4
Therefore, it took the plumber 4 hours to complete the job.