Suppose you are building a brick border for a garden by stacking rows of bricks on top of each other. if the height of each brick is 2.5 inches an r represents the number of rows, which algebraic expression would represent the height of the brick wall? explain why it's 2.5r

A single row of bricks is 2.5 inches tall. if another row is stacked on top of the first row, the total height would be 5 inches. R represents the number of rows and 2.5 represents the height of the bricks, using the equation 2.5r takes the total amount of rows and multiplies it by the height of the bricks to give you the  total height of the bricks.

Math is a complex, but faster way of doing addition. If a single row is laid the total height would be 2.5 inches, if another row is laid on top another 2.5 inches is added to the total height which would equal 5, the equation 2.5r takes the amount of rows and uses multiplication to quickly add up the total height of the bricks, so it isn't necessary to add up each individual row's height.

So i wrote so much, I am trying to explain as thoroughly as possible.  

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graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.