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.
The first equation is 
(Equation 1)
The second equation is
(Equation 2)
Putting the value of x from equation 1 in equation 2.
we get,


by simplifying the given equation,


Using discriminant formula,


Now the formula for solution 'x' of quadratic equation is given by:


Hence, these are the required solutions.
Answer:
x=2
Step-by-step explanation:
this is just like the last one. since it is vertical it only includes the x value 2