Answer:
C=5.1
Step-by-step explanation:
Using pythag (a²+b²=c²) we can determine c.
1²+5²=26
√26 = 5.099
c=5.1
You can find this out by finding common denominators.
multiply 6/10 by 3/3 to get 18/30
multiply 9/15 by 2/2 to get 18/30
they both equal 18/30 so they are the same
DF = DE + EF
So,
DF = 47 + 3x +10
We know that DF = 9x - 39, so:
9x - 39 = 47 + 3x + 10
9x - 3x = 57 + 39
6x = 96
x = 16
EF = 3x + 10
EF = 3.16 + 10
EF = 48 + 10
EF = 58
It's fine :)