The measure of the two sides of a triangle.

A.

Step-by-step explanation:

The answer is A because well 3x would not change and 17x would not change but 7 and 5 would change because they are not variable numbers So when u do the mah you would get 3x2+17x -2

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -

ok thats very interesting