Q:

Lila wrote an equation of the cost for printing brochures, where x represents the number of brochures and y represents the total cost. The total cost for 35 brochures is $41.45. The total cost for 65 brochures is $55.55. Step 1: Write the ordered pairs mc017-1.jpg and mc017-2.jpg.Step 2: Find the slope. mc017-3.jpgStep 3: Find the y-intercept to write the equation in slope intercept form. mc017-4.jpgWhich explains the error that Lila made? Lila made in error in Step 1 by reversing the ordered pairs.Lila made an error in Step 2 by not using the slope formula.Lila made an error in Step 3 when she did not use the x- and y-coordinates from the same ordered pair.

Accepted Solution

A:
Answer:y = 0.47x + 25y1 = 41.45 and not 55.55Step-by-step explanation:Given that:x = number of brochuresy = total. CostTotal cost of 35 brochures = $41.45Total cost of 65 brochures = $55.55The ordered pairs :(x1, y1) ; (x2, y2)x1 = 35 ; y1 = 41.45 ; x2 = 65 ; y2 = 55.55(35, 41.45), (65, 55.55)The slope :Slope (m) = change in y / change in xm = (y2 - y1) / (x2 - x1)m = (55.55 - 41.45) / (65 - 35)m = 14.1 / 30m = 0.47The y intercept :y - y1 = m(x - x1)y - 41.45 = 0.47(x - 35)y - 41.45 = 0.47x - 16.45y = 0.47x - 16.45 + 41.45y = 0.47x + 25Lila incorrectly chose 41. 45 as y1