Answer:
5
Step-by-step explanation:
total sum of the 6 numbers
= 4 ×6
= 24
sum of numbers without the two 2s
= 24 - 2(2)
= 20
average of other 4 numbers
= 20 ÷ 4
= 5
Answer:
Step-by-step explanation:
12a)To rationalize the denominator, multiply the denominator and numerator by √5.

b) (a+b)² = a² + 2ab + b²
(1 +√3)² = 1² + 2*1*√3 + (√3)²
= 1 + 2√3 + 3
= 4 + 2√3
a = 4 ; b =2
13) (a + b)(a - b) = a² - b²

Answer:
Correct choice is B
Step-by-step explanation:
Let a, b, c and d be the trapezoid's sides lengths.
The perimeter of the trapezoid is the sum of all sides lengths, thus,

If each side length is increased by a factor 7, then new sides have lengths 7a, 7b, 7c and 7d. The perimeter of new trapezoid is

Use the distributive property for this expression:

Since
then

Based on the picture, we know that ED is equal to DB. Therefore:
2 times ED=EB
2(10)=20
EB is 20