Question

Marcus has 2 sisters.The sum of the girls' ages is 13.The product of their ages is 36.How old is each sister?

Answer 1

Let the age of the sisters as a and b.
then,
a+b=13 and a*b=36
this implies a=13-b. hence (13-b)(b)=36.

solve it then u get the answer

Answer 2

Say one sister is Z and another sister is Y. You'd have to make a simultaneous equation, so it would be:
Z+Y=13
ZY=36
You could solve it multiple ways, but the way I think is easiest would be substitution.
Basically, if you used substitution, you would get Y=13-Z (because you solved for Y).
Then you'd take that answer (13-Z) and substitute it for Y in the second equation. You'd then get:
Z times (13-Z) = 36. So then you would just solve.

Answer 3

still no clue ....

Answer 4

Z*(13-Z)=13Z-Z^2.
13Z-Z^2=36.
Then you can factor I think.
So:
-Z^2+13Z-36=0
But we don't want a negative Z^2, so we have to flip all of the signs. Now we get:
Z^2-13Z+36=0.
Then factor. Because 13Z is negative and 36 is positive, you're going to have two negative answers in your factors. What two numbers multiply to 36 and add up to -13?
-9 and -4. So Z can either equal 9 or 4, because you have to flip the signs. (And that should be apparent because you can't be a negative age.)
So the sisters are aged 9 and 4.
I hope that makes sense.. I haven't done that kind of equation in forever, but I think it's right.

Answer 5

thy...me too this is for my daughter she is in 4 g and I'm out of school for over 30 years..lol

Answer 6

yes.sarahlynn is right. the answer should be 4 and 9 years old.

Answer 7

thank you this is the Destiny so one is 9 and the other one is 4 because 9*4=36 and 4*9=36 right so this would be right!!!