Question 147652
Let the two angels be a and b

a+b = 215

We are also given a second set of information
The supplement of an angle plus the angle is always 180.

We are told {{{(3/5)*(180-a) + (2/3)*(180-b) = 91}}}

{{{108 - (3/5)a + 120 - (2/3)b = 91}}}
{{{-(3/5)a - (2/3)b = -137}}}
{{{9a + 10b = 2055}}}

Now solve using
{{{9a + 10b = 2055}}}
{{{a + b = 215}}}

*[invoke solving_linear_system_by_elimination 9, 10, 2055, 1, 1, 215]

To get a = 95 and b = 120