Using appropriate properties of rational numbers, find the sum 34+421+78+57

Geometry? i am really bad at math and have dyscalcullia. .

Aconvex octagon has interior angles that measures 73 degrees, 172 degrees, 132 degrees, 59 degrees, 154 degrees, 163 degrees, x degrees, 2x degrees find the value of the missing angles

7. if the value of x varies directly with the value of y, and x = 3 when y = 21. what is the valu y, and x = 3 when y = 21. what is the value of x when y = 105?