I hope that 2-1 means 21.
DE + EF = DF
4x + 10 + 21 = 9x - 15
4x + 31 = 9x - 15
31 = 9x - 4x - 15
31 = 5x - 15
46 = 5x
x = 9 1/5 = 9.2
You want 9x - 15
9*9.2 - 15
82.8 - 15
67.8 <<<<< answer.
If I have given the wrong meaning to 2-1 (which could mean 1) leave another note and I will correct my work.
Answer:
-x - 3y + z
Step-by-step explanation:
Think of a imaginary 1(-1 because of the sign) in front of the parenthesis and distribute it to the other number and so x will become -x, 3y will become -3y and -z will become z because two negatives make a positive.
Answer:

Step-by-step explanation:
I hope it helped U
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