Just number 7, quickly i don’t know what i’m doing (if you give an explanation i’ll mark as brainliest)

x=12

Step-by-step explanation:

x+5+3x+10=x+51

Step 1- Simplify

15+4x=x+51

Step 2- Move the variable to one side  

15+4x=x+51  

    -1x -1x

15+3x=51

Step 3- Subtract

15+3x=51

-15       -15

3x=36

Step 4- Divide

3x=36

3    3

Conclusion-- x=12

a 270° rotation about point p says on e d g e n u it y (had to space it out because it says it's a misspelling so i couldn't submit it

it will cost dollar $540

the living room is 3 which means if we divide 325/3 then we get $108

therefore if 1part of the living room cost $108 and 3 costed $325

then total 5part of the room will cost 5*108 which gives $540