Answer:
1st one:
37 - 25 = 12
2nd one (to the right of the one on the top-left):
(19 - 10) - 7 = 2
3rd one (below the one of the top-left):
Since BD = 13 and CD = 10, BC must equal 3.
AC would equal the sum of 8 and 3.
8 + 3 = AC
11 = AC
4th one:
Not exactly sure what you want to find here, add more info.
But if you want to find the middle or mid-point:
10 + 3x + 5 = 25
15 + 3x = 25
3x = 10
Divide by 3 on both sides:
x = 3.33 or 31/3 or 10/3
5th one (bottom-left):
*First find x*
9 + x + 2x - 3 = 30
6 + 3x = 30
3x = 24
Divide both sides by 3:
x = 8
*Now that you have x, you can find the length of DE:
2(8) - 3 = DE
16 - 3 = DE
13 = DE