Answer:
9y(2x - 1)(x - 2y)(x + 2y)
Step-by-step explanation:
Given
18x³y - 9x²y - 72xy³ + 36y³ ← factor out 9y from each term
= 9y(2x³ - x² - 8xy² + 4y²)
Factor the first/second and third/fourth term in the parenthesis
= 9y( x²(2x - 1) - 4y²(2x - 1)) ← factor out (2x - 1) from each term
= 9y(2x - 1)(x² - 4y²)
x² - 4y² is a difference of squares and factors in general as
a² - b² = (a - b)(a + b), thus
x² - 4y²
= x² - (2y)² = (x - 2y)(x + 2y), hence
18x³y - 9x²y + 72xy³ + 36y³
= 9y(2x - 1)(x - 2y)(x + 2y) ← in factored form
A:
Ratio of all students in the class to girls is...
15:8
b:
Ratio of boys to girls....
7:8
For example, the probability of an outcome of heads on the toss of a fair coin is ½ or 0.5. The probability of an event can also be expressed as a percentage (e.g., an outcome of heads on the toss of a fair coin is 50% likely) or as odds (e.g., the odds of heads on the toss of a fair coin is 1:1).
