I need to see the directions
5(n-4)=(4n-12)
First: Distribute 5 into n and -4.
5(n-4)=(5n)+(5*-4)= 5n-20.
Second: Subtract 4n from both sides to eliminate the variable from the right side of the equation.
(5n-20)=(4n-12)
n-20=-12
Next: Add 20 to both sides to eliminate the constant from the left side of the equation.
n-20=-12
n=8
The unknown number is 8.
Our discriminant is 0 so,
has one real root.
Option C is correct.
Step-by-step explanation:
we need to find the discriminant and the number of real roots for the following equation:

The discriminant is found by using square root part of quadratic formula:

where b =12, a=4 and c=9
Putting values:

To find out the number of real roots using discriminant we have following rules:
- if discriminant b^2-4ac >0 then 2 real roots
- if discriminant b^2-4ac =0 then 1 real root
- if discriminant b^2-4ac <0 then no real roots
Since our discriminant b^2-4ac is 0 so,
has one real root.
Option C is correct.
Keywords: discriminant
Learn more about discriminant at:
#learnwithBrainly
Answer:
<h2>
512 m²</h2>
Step-by-step explanation:
The surface area is a sum of areas of four triangles with base of <em>8 m</em> and hight of <em>12 m</em> and areas of five squares with sides of <em>8 m.</em>
<em />
<h3>
Sa = 4×¹/₂×8×12 + 5×8² = 192 + 320 = 512 m²</h3>