1) it must be fulfilled that the denominator is different from zero, then for this expression
x^2 -9 ⇒ x^2-3^2 = (x-3)(x+3)⇒ (x-3)(x+3) = 0 ⇒ x = 3 o x = -3 , the dominium is all numbers reals except 3 and -3
Answer:
Step-by-step explanation:
Let the equal number of hours be represented by variable H;
The two equations will be as follows;
Jack; 40 +30H
Mark; 50 +25H
Next, equate them;
40 + 30H = 50 + 25H
30H - 25H = 50 - 40
5H = 10
H =10/5
H = 2hrs
Therefore, they charge the same amount at 2 hrs.
B.) The amount charged;
Replace the variable H in any of the two equations above with 2 to solve for the amount.
Equation 40+30H = 40 + (30*2)
=40 + 60
= $100
They aren't necessarily equal because, for example, 3/2 = 1 remainder 1 and 5/4 = 1 remainder 1 aren't equal because it takes 2 x 1 = 2 + 1 = 3 while 4 x 1 = 4 + 1 = 5. They are the same quotient and remainer, except they aren't used to check if it multiplys back to the same divended.
