Question 1197241
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<table border = "1" cellpadding = "5"><tr><td>Rate</td><td>Formula</td></tr><tr><td>Grows 4 feet every year</td><td>H(t) = 4t+7</td></tr><tr><td>Grows 4 feet every 5 years</td><td>H(t) = (4/5)t+7</td></tr><tr><td>Grows 1 foot every 5 years</td><td>H(t) = (1/5)t+7</td></tr></table>Side note: 4/5 = 0.8 and 1/5 = 0.2


Each equation is of the form y = mx+b
y = H(t) = height at time t
m = slope = tells us how fast the tree is growing
x = t = input time value, in years
b = starting height = 7 for each equation


If a tree grows 4 feet every 5 years, then it grows 1 foot every 4/5 = 0.8 years.


If needed, we can make a table of values. 
Here's a sample table for the third formula
<table border = "1" cellpadding = "5"><tr><td>t</td><td>H(t) = (1/5)t+7</td></tr><tr><td>0</td><td>7</td></tr><tr><td>1</td><td>7.2</td></tr><tr><td>2</td><td>7.4</td></tr><tr><td>3</td><td>7.6</td></tr><tr><td>4</td><td>7.8</td></tr><tr><td>5</td><td>8</td></tr><tr><td>6</td><td>8.2</td></tr><tr><td>7</td><td>8.4</td></tr><tr><td>8</td><td>8.6</td></tr><tr><td>9</td><td>8.8</td></tr><tr><td>10</td><td>9</td></tr></table>Each time we reach a multiple of 5, we get to another whole number for H(t)
In other words
t = 0 leads to H(t) = 7
t = 5 leads to H(t) = 8
t = 10 leads to H(t) = 9
I'll let you generate the other tables if your teacher requires it.
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