Step-by-step explanation:
here is the answer for your question
long way
12 x 11 x 10 x 9 x 8 x 7 x6 x5 x4 x3x2/ 10x9x8x7x6x5x4x3x2x
but you can shorten that by crossing out identical numbers so you get 12 x 11
12 x 11 = 132 combinations
Thirteen plus seven is twenty. One fourth of twenty is five.
The answer is five.
Answer:
x = -
, x = 
Step-by-step explanation:
Given
x² - x -
= 0
Multiply through by 4 to clear the fraction
4x² - 4x - 3 = 0
Consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term
product = 4 × - 3 = - 12 and sum = - 4
The factors are + 2 and - 6
Use these factors to split the x- term
4x² + 2x - 6x - 3 = 0 ( factor the first/second and third/fourth terms )
2x(2x + 1) - 3(2x + 1) = 0 ← factor out (2x + 1) from each term
(2x + 1)(2x - 3) = 0
Equate each factor to zero and solve for x
2x + 1 = 0 ⇒ 2x = - 1 ⇒ x = - 
2x - 3 = 0 ⇒ 2x = 3 ⇒ x = 
No, You only reverse the inequality symbol when you divide by a negative number.