Answer: 69
Step-by-step explanation: a triangle adds up to 180 degrees. It is an isosceles triangle (2 sides are the same angle) 180-42=138 then do 138/2=69
Answer:
k=10
Step-by-step explanation:
4k + 12= 52
minus 12 on both sides
4k=40
now divide by 4
k=10
Answer:
81 900 000 000 000 is 8.19 × 10¹³
Step-by-step explanation:
Write the first number 8.
Add a decimal point after it: 8.
Now count the number of digits after 8. There are 13 digits.
So, in standard form: 81 900 000 000 000 is 8.19 × 10¹³
Answer:
4004
Step-by-step explanation:
The number of combinations of choosing r objects from a group of n is nCr.
So the number of ways to get 7, 8, 9, or 10 heads from 13 coin tosses is:
₁₃C₇ + ₁₃C₈ + ₁₃C₉ + ₁₃C₁₀
= 1716 + 1287 + 715 + 286
= 4004
