D) Seven years ago, father was seven times as old as his son was. Three years hence, he will be three times as old as his son. Find their present age.​

son is 12, father is 42

Step-by-step explanation:

where x = son's age and y is the father's age

Step-by-step explanation:

let Y is the age of the father

let x is the age of the son

b is 38 degrees.

a is 52 degrees.

this is because if b is 38 and a is 14 degrees more than b than 38+14=52 and 52+38=90 degrees. hope this .

answer: y = -2.5x - 15

              (-6,0)

step-by-step explanation: