Step-by-step explanation:
Choosing 4 digits out of 10 = 10C4 = 210.
Arranging the 4 digits in 4 places = 4!
Total number of ways to arrange digits
= 210 * 4! = 5040.
Choosing 2 letters out of 26 = 26C2 = 325
Arranging the 2 letters in 2 places = 2!
Total number of ways to arrange letters
= 325 * 2! = 650.
Total number of possible license plates
= 5040 * 650 = 3,276,000.
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
it lost 128 gallons in 16 days so divide 128 by 16 to find the daily lost
128/16 = 8 gallons a day were lost
You multiply and add like terms, depending on the equation that you have
9/21 as the original
1/7 is the simplified version