Perimeter of triangle = all sides added up
3a + 4 + 2a - 7 + 9a + 11
now add like terms
3a + 2a + 9a = 5a + 9a = 14a
4 - 7 + 11
= -3 + 11 = 8
so we have 14a + 8
as our simplest expression
Since there are three black shirts and 7 blue shirts, he has a 3/10 chance of picking a black.
3^6 power. it would be 3 to the 6th power
