The product of a number and two more than the number .. what is the expression?

What is the missing reason in step 5? linear pair postulategivendefinition of complementary anglescongruent complements theorem

Jackie purchased 3 bottles of water and 2 cups of coffee for a family for $7.35. brian bought 4 bottles of water and 1 cup of coffee for his family for $7.15. how much does each bottle of water cost? how much does each cup of coffee cost? i need this done

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0