Answer:
Size of each group = 
Step-by-step explanation:
Total number of paint brushes = x
Since each the three groups are equally sized, to get the number of paintbrushes in a group, we will have to divide the total number of paint brushes by 3
∴ We have, number of paint brushes in a group = 
=
this is also the same thing as saying 
×
This shows that the size of the new group is the same as the size of the original group
The word "associative" comes from "associate" or "group";the Associative Property is the rule that refers to grouping. For addition, the rule is "<span>a + (b + c) = (a + b) + c</span><span>"; in numbers, this means
</span>2 + (3 + 4) = (2 + 3) + 4. For multiplication, the rule is "<span>a(bc) = (ab)c</span>"; in numbers, this means2(3×4) = (2×3)4<span>. Any time they refer to the Associative Property, they want you to regroup things; any time a computation depends on things being regrouped, they want you to say that the computation uses the Associative Property.</span>
We have similar triangles so
12/x = (12+78)/(x+13)
We can skip some algebra by doing the ratio on the pieces. We'll show it works at the end.
12/x = 78/13
x = 12(13)/78 = 2
We check
12/2 = 6
(12+78)/(2+13) = 90/15 = 6, good
Answer: x=2
1) find the lcd the lcd is 12
2)rewrite the fractions 1/4 and 2/3 using 12 as the denominator (second column) you get 3/12 and 8/12
3) since its confusing to subtract 8/12 from 3/12 you need to borrow one form the 126 doing so is the same as taking 12/12 from 126 this change to 125 and the 12/12 adds to the 3/12 making it 15/12
4) subtract 8/12 form 15/12 to get 7/12
5) subtract 78 form 125 to get 47
6) the answer is 47 7/12
