Just matter of combining like terms
6x - 7 - 11x + x =
(6x + x - 11x) - 7 =
(7x - 11x) - 7 =
- 4x - 7 <===
4.5 and 3.25 gets you to 7.75, you are correct
The answer is 38,400
The scale is 1:40 so the side that is 4 in becomes 160 and the side that is 6 in becomes 240
Multiply 160 and 240 and that is the area of the room
Hope this helps
Answer:

Step-by-step explanation:
Given

Required
The period
A sine function is represented as:

Where

By comparing:
and 

So, we have:


Hence, the period of the function is 
Answer:
-4 or 5
Step-by-step explanation:
let number be x
x²-x=20
Rearrange
x²-x-20=0
(x+4)(x-5)=0
Separate
x+4=0, x-5=0
x=-4 or 5