No a biased sample is not valid
Answer:
(a + 2b)(a - b)
Step-by-step explanation:
Assuming you require the expression to be factored
Given
a² +
ab - b² ← factor out
from each term
=
(a² + ab - 2b²) ← factor the quadratic
Consider the factors of the coefficient of the b² term(- 2) which sum to give the coefficient of the ab- term (+ 1)
The factors are + 2 and - 1, since
2 × - 1 = - 2 and 2 - 1 = + 1, thus
a² + ab - 2b² = (a + 2b)(a - b) and
a² +
ab - b² =
(a + 2b)(a - b)
Answer:
Jacob ran 40 yards more than Ali.
Step-by-step explanation:
Football field is in the shape of a rectangle having dimensions 120 yards × 50 yards
Since Jacob runs around the perimeter of the field from one corner to other corner, therefore, distance run by Jacob = 
Distance run by Jacob = 50 + 120 = 170 yards
Ali runs through the middle of the field diagonally on a straight line.
Therefore, distance covered by Ali = 
= 
= 
= 
= 130 yards
Now difference between the distance covered by Jacob and Ali
= 170 - 130
= 40 yards
Therefore, Jacob ran 40 yards more than Ali.
The best arrangement can be
- 3 rows and 4balls each row
So
- Length of one row=1.8(4)=7.2cm
- Width=1.8(3)=5.4cm
- Height=1.8(2)=3.6cm
So
TSA
- 2(LB+BH+LH)
- 2(5.4(7.2)+(7.2)(3.6)+3.6(5.4))
- 2(84.24)
- 168.48cm²
Total cost