Amother who is 40 years old has a daughter and a son. the son is twice as old as the daughter. in 15 years the sum of all their ages will be 100 years. how old are the siblings now?

15 and 5

Step-by-step explanation:

Mother's current age:  40

daughter's age:  d

son's age:  s

son is 2x as old as daughter:  s = 2d

Then, 15 years from now, the sum of their ages will be:

(40 + 15) + (2d + 15) + (d + 15) = 100

or

55 + 15 + 15 + 3d = 100

85 + 3d = 100, or 3d = 15, or d = 5.

Then the son's age is 3(5) = 15 and the daughter's is 5.

42

step-by-step explanation:

(23*2)-12=x     x=34

step-by-step explanation: