Answer:
a. =11+ 1
b. =4x+ (-7y) + (-5z) +6
c. (-3x) + (-8y) +(-4)+(-8/7z)
Step-by-step explanation:
a. 20 - 9 + 8 -7
=11+ 1 ( this is obtained by solving)
b. 4x - 7y - 5z + 6
=4x+ (-7y) + (-5z) +6
We multiply the negative sign with the positive sign to get a minus so the answer remains the same and the expression is written as an addition sum.
c. -3x - 8y - 4 - 8/7z
-[ 3x+8y+4+8/7z]
or
(-3x) + (-8y) +(-4) +(-8/7z)
The minus sign is taken as common leaving the expression with the plus only.
It can be written in the same manner as above, adding the negative terms so that the expression is written as a sum.
143 seats
because 2920 seats/20 sections=143 seats in each section
Answer:

Step-by-step explanation:
Answer:
There are 6 slices left.
Step-by-step explanation:
The remaining slices are:
Carrot Cake


Chocolate Cake


There are 6 slices left.
Answer:
1. {5,-9}
2.{4}
3.{9/2}
Step-by-step explanation:
The equation
can be solved as follows:




Then, the solutions of the equation are
.
Now, if
, we can solve the equation
as follows:




So, the unique solution of this last equation is 
The last equation is
, where
. To solve this equation we can proceed as follows:







But, x=11/4 is not a solution of this equation. So the unique solution is x=9/2.