please help me!!

Question

Sarah, Lacey, and Mark stuffed envelopes with invitations for parents to an open house.
• Sarah stuffed 10 more envelopes than Lacey.
• Mark stuffed 3 less than twice as many envelopes as Lacey.
• Altogether they stuffed 503 envelopes.
If x represents the number of envelopes that Lacey stuffed, which equation best represents this
situation?

Answer 1

Dayana,

 

I think you are missing some information (the equations which best represents this situation).  So here is a solution:

 

 

Let x = number of envelopes Sarah stuffed

Let y = number of envelopes Lacey stuffed

Let z = number of envelopes Mark stuffed.

 

Since Sarah stuffed 10 more than Lacey:

     x = y + 10    eqn (1)

 

Since Mark stuffed 3 less than twice Lacey:

     z = 2y - 3     eqn (2)

 

All together, 503 envelopes were stuffed means:

     x + y + z = 503   eqn (3)

 

Substitute x = y + 10 and z = 2y - 3 into eqn (3) yields:

     (y + 10) + y + (2y - 3) = 503

     4y + 7 = 503

     4y = 496

     y = 124 envelopes

 

Solve for x using eqn (1):

     x = y + 10 = 124 + 10 = 134 envelopes

 

Solve for z using eqn (3):

     x + y + z = 503

     134 + 124 + z = 503

     Z = 245 envelopes

 

Hope this helps!

Answer 2

 

Set x the number of envelopes that Lacey stuffed, then

 

[ x ] + [ x + 10 ] + [ 2x - 3 ] = 503 this is the equation that best represents this situation.

 

4x + 7 = 503

 

4x = 496

 

x = 124 envelopes <------ Lacey

      134  envelopes<------ Sarah

      245  envelopes<------ Mark

Answer 3

x = number of envelopes stuffed by Lacey

S = number by Sarah =  x + 10

M = number by Mark =   2x -3

 

S     +    M      +    L = 503

^           ^

x+10   +  2x -3 +   x = 503

 

combine like terms: 

4x + 7 = 503 

4x = 496

x = 124 >>> Lacey's

x + 10 = 134 >>>Sarah's

2x - 3 = 245 >>> Mark's