Which phrase represents the algebraic expression 5x - 9? a. the product of five times a number and nine b. the difference of nine times a number and five c. the sum of five times a number and five d. the difference of five times a number and nine

D. the difference of five times a number and nine

Step-by-step explanation:

"Five times a number" is written as 5x.  This is because the number itself is unknown, so we use a variable.

"Difference" means subtraction; thus "The difference of five times a number and 9" would be 5x-9.

it would open into a square depending on the type of envelope i’m not sure about the second part

step-by-step explanation:

the triangles are similar. therefore the corresponding sides are in proportion:

              cross multiply

            divide both sides by 32