Please Help 6-10 or just one of them

6) 20

7) I think is 2.5 (im not sure)

8) 7

Step-by-step explanation:

6) (5x+9)+(3x+11)=180

    8x+20=180

         -20   -20

          8x=160

Divide 8 on each side

            x=20

7) (17x+1)=(20x-14)

   17x+15 =20x

   +17         +17

     15 = 37x

divide 15 on each side

X=2.5

8) (3x+3)+(10-4)=90

    (3x)+(10x-1)

      13x-`1=90

            +1   +1

         13x=91

Divide 13 on each side

x=7

2

step-by-step explanation:

the answer for this question is : 360°

step-by-step explanation:

we have been given a triangle   we need to tell which one of these is a triangle below to map onto itself.

360° rotation is the complete rotation which eventually leads to the same figure which is given.

the correct will be, that is 360° that will cause the triangle below to map onto itself.