How can i compare the method of using expanded form and the method of using place value to multiply a decimal and a whole number

After applying the composition r0.90 ry to rs what are the coordinates of r' and s'? a. r'(–3, 1),  s'(–3, 5)b. r'(–1, 3),  s'(–5, 3)c. r'(1, 3),  s'(5, 3)d. r'(5, 3),  s'(1, 3)

Write a corresponding real world problem to represent 2x - 125=400

The price of a dozen eggs was $1.63. suppose the price increases m dollars per dozen and then the price decreases $0.12 per dozen. which expression represents the current price of eggs after the two price changes?