Use the associative property of addition to rewrite (12+3)+7. Which expression is equivalent?

A. 12(3 + 7)

B. (5 + 5 + 3) + 7

C. (12 - 3) + 7

D. 12 + (3 + 7)

its D

Step-by-step explanation:

Its the only one that makes sense and B is definitely not the answer

Ap3x and coral confirm this

25x + 15y = 265

x+y = 13

Step-by-step explanation:

Step 1:

Given

Number of shirts Leah can iron in an hour = 25 shirts

Number of shirts Christopher can iron in an hour = 15 shirts

Total number of hours worked by both = 13 hours

Total number of shirts ironed by them = 265 shirts

Step 2 :

Let x represent the number of hours Leah works and y represent the number of hours Christopher works

Leah irons 25 shirts in one hour, so in x hours he would iron 25x shirts

Christopher irons 15 shirts in one hour, so in y hours he would iron 15y shirts

Given total shirts ironed by them together is 265 , we have

25x + 15y = 265

They worked a combined of 13 hours, so

x+y = 13

Step 3:

The system of equations that could be used to determine the number of hours Leah worked and the number of hours Christopher worked are ,

25x + 15y = 265

x+y = 13