Answer:
9x-1
Step-by-step explanation:
The perimeter of the triangle is adding up all 3 sides.
(3x)+(x+6)+(5x-7)=P
9x-1 = perimeter
All I have done is combine like terms.
If there is a... x = something, replace x with the number.
a) the cost of a bunch of grapes compared with its weight
Answer:

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Add up the corresponding elements
Row1,Column1: 6.1+(-7.2) = -1.1
Row1,Column2: 1.9+7.6 = 9.5
Row2,Column1: -7.5+1.8 = -5.7
Row2,Column2: 2.2+(-1.4) = 0.8
Row3,Column1: 3.8+2.3 = 6.1
Row3,Column2: -1.4+2.1 = 0.7
So that's why the answer is