The local craft store purchased 7 boxes of red yarn , 5 boxes of yellow yarn , and 12 boxes of blue yarn. each box contains 25 balls of yarn. how many balls of blue and red yarn did they order ?

Ignore the boxes of yellow yarn, they're insignificant.

If each box has 25 balls in it, you would multiply the number of boxes by 25

First do the red balls: 7 x 25= 175

Then the blue: 12 x 25= 300

Now you add the red balls and the blue balls.

They ordered 475 balls of blue and red yarn. Or 300 blue and 175 red