Given:
The equation is

To find:
The number of roots and discriminant of the given equation.
Solution:
We have,

The highest degree of given equation is 2. So, the number of roots is also 2.
It can be written as

Here,
.
Discriminant of the given equation is





Since discriminant is
, which is greater than 0, therefore, the given equation has two distinct real roots.
Answer:
Given System of equation:
x-y =6 .....,[1]
2x-3z = 16 ......[2]
2y+z = 4 .......[3]
Rewrite the equation [1] as
y = x - 6 .......[4]
Substitute the value of [4] in [3], we get

Using distributive property on LHS ( i.e,
)
then, we have
2x - 12 +z =4
Add 12 to both sides of an equation:
2x-12+z+12=4+12
Simplify:
2x +z = 16 .......[5]
On substituting equation [2] in [5] we get;
2x+z=2x -3z
or
z = -3z
Add 3z both sides of an equation:
z+3z = -3z+3z
4z = 0
Simplify:
z = 0
Substitute the value of z = 0 in [2] to solve for x;

or
2x = 16
Divide by 2 both sides of an equation:

Simplify:
x= 8
Substitute the value of x =8 in equation [4] to solve for y;
y = 8-6 = 2
or
y = 2
Therefore, the solution for the given system of equation is; x = 8 , y = 2 and z =0
You would subtract 11 on both sides of the equation.
Then multiply the reciprocal of 1/2 which is 2.
And you should get -16 as your answer <span />