The answer is C 16:20 because both numbers 4&5 are multiplied by four
Answer:
Age of Mark
years
Age of Mark's dad
years
Age of Mark's sister
years
Step-by-step explanation:
Let age of Mark be
years.
Mark's dad is three times older than Mark
Age of her Mark's dad 
Mark's sister is 2 years younger than Mark
Age of Mark's sister
years
The sum of their ages is 48.

Age of Mark
years
Age of Mark's dad
years
Age of Mark's sister
years
Answer:
Learn how to find the distance between two points by using the distance formula, which is an application of the Pythagorean theorem. We can rewrite the Pythagorean theorem as d=√((x_2-x_1)²+(y_2-y_1)²) to find the distance between any two points. Created by Sal Khan and CK-12 Foundation.
The Pythagorean Theorem is a^2 +b^2 = c^2, where a and b are the sides and c is the hypotenuse ( angled line).
3.
a^2 + 6^2 = 18^2
a^2 + 36 = 324
a^2 = 324 - 36
a^2 = 288
a =√288
a = 12√2
4.
a^2 + 3^2 = 9^2
a^2 + 9 = 81
a^2 = 81-9
a^2 = 72
a = √72
a = 6√2