The floor of a canyon has an elevation of -6.5 feet erosion causes the elevation to change by -0.25 feet per year. how many years will it take for the canyon floor to have an elevation of -20 feet.

54

Step-by-step explanation:

20 - 6.5 = 13.5

13.5 / 0.25 = 54

It would take 54 years for the canyon to erode 13.5 more feet to bring to -20 elevation.

2/3x + 7 = 29

step-by-step explanation:

two thirds = 2/3

plus a number = x

at least 29 = 29

there for you should get 2/3x + 7 = 29

x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

step-by-step explanation:

last month maria hiked the 5-mile mountain trail a number of times and she hiked the 10-mile canal trail several times. let x represent the number of times she hiked the 5-mile trail, and let y represent the number of times she hiked the 10-mile trail. if she hiked a total of 90 miles, which equation can be used to find the number of times maria hiked each trail? x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x