Four friends are playing a "Guess my Age" game. The come up with the following clues. Dave's age is 15% of Sabrina. Luca's age is 75% of Sabrina and Rhianna is 300%
of Dave. The sum of their ages is 141. How old is Rhianna?
Show your work!

27 years old

Step-by-step explanation:

What I know

Let D = Dave, S = Sabrina, etc. Then:

(1)

(2)

(3)

(4)

Want to find R. Taking equation 3 and rewriting equation 4, we get

So if , then

by adding to both sides.

Using equation 1 and equation 2, I can rewrite everything in terms of and get:

by adding to both sides.

by dividing 2.35 both sides.

Now that I know Sabrina's age, I'll work towards getting Rhianna's using equation 1 and equation 3:

Checking my work:

Dave: 9

Sabrina: 60

Luca: 45 (since 9+60+45+27=141)

Rhianna: 27

9 is 15% of 60

45 is 75% of 60

27 is 300% of 9

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

answer   download the app called socratic on your phoner:

step-by-step explanation: