Bridges on highways have expansion joints, which are small gaps in the roadway between one bridge section and the next. the gaps are put there so the bridge will have room to expand when the weather gets hot. suppose a bridge has gap of 1.4 cm when the temperature is 30c, and that the gap narrows to 0.9 cm when the temperature warms to 40c.
find the rate of expansion from 20c to 30c do not round

0.5 cm per 10 degrees

0.05 cm per one degree.

Step-by-step explanation:

For 30 degrees the bridge has a gap of 1.4 cm

For 40 degrees the bridge has a gap of 0.9 cm

The bridge expanded

1.4 cm - 0.9  cm = 0.5 cm per 10 degrees

Or, likewise

0.5/10 = 0.05 cm per one degree.

This means that for each degree that the temperature increases, the bridge will expand 0.05 cm

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