A truck that can carry no more than 5900 lb is being used to transport refrigerators and upright pianos. Each refrigerator weighs 250 lb and each piano weighs 525 lb. Write and graph an inequality to show how many refrigerators and how many pianos the truck could carry. Will 12 refrigerators and 7 pianos overload the​ truck? Explain.

3 answers

Let x be the number of refrigerators and y be the number of pianos. Then we can write the inequality:

250x + 525y ≤ 5900

To graph this inequality, we can plot the boundary line 250x + 525y = 5900 (which represents the maximum weight the truck can carry) as a dashed line, since it does not include the points on the line. Then we can shade the region below the line, since any point in this region will satisfy the inequality.

To determine if 12 refrigerators and 7 pianos will overload the truck, we can substitute x = 12 and y = 7 into the inequality:

250(12) + 525(7) = 5900

This shows that the weight of the refrigerators and pianos combined is exactly equal to the maximum weight the truck can carry. Therefore, the truck would not be overloaded by carrying 12 refrigerators and 7 pianos.
A truck that can carry no more than 5900 lb is being used to transport refrigerators and upright pianos. Each refrigerator weighs 250 lb and each piano weighs 525 lb. Write and graph an inequality to show how many refrigerators and how many pianos the truck could carry. Will 12 refrigerators and 7 pianos overload the​ truck? Explain.
Write an equation in slope-intercept form.
The inequality is 250x + 525y ≤ 5900, where x is the number of refrigerators and y is the number of pianos.

To graph this inequality in slope-intercept form, we need to solve for y:

250x + 525y ≤ 5900

525y ≤ -250x + 5900

y ≤ (-250/525)x + (5900/525)

y ≤ (-10/21)x + (112/21)

The slope of the line is -10/21 and the y-intercept is 112/21. We can plot the y-intercept on the y-axis and then use the slope to find additional points and draw a line. The inequality is satisfied by all points below this line.

To answer the second part of the question:

Substituting x = 12 and y = 7 into the inequality, we get:

250(12) + 525(7) = 5900

Since the weight of the refrigerators and pianos combined is exactly equal to the maximum weight the truck can carry, carrying 12 refrigerators and 7 pianos will not overload the truck.