Answer:
x = - 
, x = 
Step-by-step explanation:
Given
x² - x - 
= 0 ( add to both sides )
x² - x =
Solve using the method of completing the square
add ( half the coefficient of the x- term )² to both sides
x² + 2( - )x + 
= +
(x - )² = 1 ( take the square root of both sides )
x - = ± 1 ( add to both sides )
x = ± 1
Thus
x = - 1 = -
x = + 1 =
(-infinity, 2]. Use the infinity symbol and not the word
Answer:
Step-by-step explanation:
2x + 9 = 15
you move + 9 to the other side of the equation, you will get:
2x = 15 - 9
2x = 6
So, x = 3
Answer:
Tamara incorrectly factored the whole expression.
Step-by-step explanation:
Note that
- 21x=3·7·x;
- 56xy=2·2·2·7·x·y.
Mark in bold all common factors, then GCF(21x,56xy)=7·x=7x.
Thus,
21x+56xy=7x(3+8y).
Hence, Tamara correctly found the GCF of numbers 21 and 56, but incorrectly factored the whole expression.
