Answer:
The age of the youngest friend is 9 years old.
Step-by-step explanation:
3a = 30 - 3
= 27 ÷ 3
= 9
= 9 + 10 + 11 = 30
= 9 is the smallest number. So, the youngest friend is 9 years old.
Answer:
7
Step-by-step explanation:
12b -b = 11b
11b = 77
Divide both sides by 11
b = 7
Answer:

Step-by-step explanation:
Angles in a triangle add up to 180°


Angles on a straight line add up to 180°


Answer:
(5, 7)
Step-by-step explanation:
M = (x1 + x2/2 , y1 + y2/2)
M = ( 4 + 6 /2 , 7 + 7 / 2)
M = 5, 7