Answer:
35 ways
Step-by-step explanation:
Alex has 9 friends and wants to invite 5 friends. Since Alex requires two of his friends who are twins to come together to his birthday party, since the two of them form a group, the number of ways we can select the two of them to form a group of two is ²C₂ = 1 way.
Since we have removed two out of the nine friends, we are left with 7 friends. Also, two friends are already selected, so we are left with space for 3 friends. So, the number of ways we can select a group of 3 friends out of 7 is ⁷C₃ = 7 × 6 × 5/3! = 35 ways.
So, the total number ways we can select 5 friend out of 9 to party come to the birthday include two friends is ²C₂ × ⁷C₃ = 1 × 35 = 35 ways
Answer:
The transformation is a rotation.
Step-by-step explanation:
Each point of triangle DEF is rotated to form 
.
letter C
1462 rounds up when looking at the tens place to 1500
Answer:
Step-by-step explanation:
for two matrices A, B to be Similar, then A = SBS⁻¹
A=SBS−1⟹trace(A)=trace((SB)(S−1))=trace((S−1)(SB))=trace((SS−1)B)=trace(B)
Answer:
-679
Step-by-step explanation:
14, 5, -4, ...
a = 14
d = 5 - 14 = -9
nth term = a + (n - 1) d
n(78) = 14 + (78 - 1) * -9
= 14 + 77(-9)
= 14 -693
= -679
