Don't know how the multiple choices are worded, but you can match the choices with these words: it is stretched along the y axis by a factor of 5. vertically stretched by a factor of 5, horizontally compressed by a factor of 5
If their ages combined equals 21 and john is twice Mary’s age then johns age takes up 2/3 of 21. that would b 14. 14 is 2 x 7. and Mary is 7. 14+7=21. Mary is 7 years old