What you need to do is take $2874 and divide the 5% and then times the 9 by what you get
-2,8 is the correct answer
Combine like terms.
2x + 6 + 6x - 1
8x + 5
I am unsure about the very last problem but I can help with the first two
1) (y+1)+4
If we combine the numbers 1 and 4, we get +5 and can isolate the numbers from the variable.
This would give us

2) (6*r)*7
remember that we do not have to explicitly state 6*r
Instead, we can write it as 6r
this helps us get rid of the parentheses
now we can write it as

I hope this helps!:)
The coordinates of the point intersection of lines (-1, -1)
If you want solve:
y = -2x - 3, y = 3x + 2
-2x - 3 = 3x + 2 |+3
-2x = 3x + 5 |-3x
-5x = 5 |:(-5)
x = -1
Put the value of x to the first equation:
y = (-2)(-1) - 3 = 2 - 3 = -1
x = -1, y = -1