The equation y= 12x + 60 can be used to estimate y, the height of a tree in centimeters x months after it is planted. When a tree is 150 cm tall, how long ago was the tree planted?

Y = the height of a tree in centimeter
x = how many months ago the tree was planted

If the question wants to know how many months ago the tree was planted (x value) if it is 150cm tall (y value) they’re asking you to plug in 150 for y, then solve for x.

y = 12x + 60
150 = 12x + 60 | subtract 60 from each side
90 = 12x | divide each side by 12
7.5 = x

x=7.5, so the tree was planted seven and a half months ago

Where are the