For Right angled triangle area
A=ab/2
(2x-2)(4x+2)/2
(8x^2+4x-8x-4)/2
(8x^2-4x-4)/2 take common term 2
2(4x^2-2x-2)/2
So A=4x^2-2x-2
I'm guessing you are having a problem with translating the problem into an equation you can solve. To help this what you can first do is underline the important parts of this problem. twice as much, 400 more,
Lets look at this
First Let the chair=x
Next we know the couch cost twice as much as the chair
So now we know we should let the couch=2x
Lastly the love seat is 400 more than the couch. couch+400is the same thing as saying 2x+400
NOw 1565=chair(x)+couch(2x)+love seat(2x+400)
So that means 1565=x+2x+2x+400
Combine like terms and you now have 1565=5x+400
Now you isolate the variable by subtracting 400 from both sides which is 1165=5x Then you divide both sides by 5 and get 223=x
12 songs. 25% of 12 is 3, so you add 3 to 12 and get 15. You then find that 20% of 15 is 3 so you subtract 3 from 15 and get 12 again.
Here u go 1.d 2.c I think 3.b
As you may know, the axis of symmetry will be a coordinate off the vertex of the equation, so...
