Explain why it does not matter what letter or symbol is used to find and unknown number?

Ivan began dividing g2  – 6 by g + 1, noting that . he started by placing g in the quotient, as shown below. what is g2  – 6 divided by g + 1? g –  1 –  g + 1  – g  –  7 + g  –  5  + 

Scale factor of 2 is used to enlarge a figure as shown below the area of is 18 in.²

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?