Solve : `4/(13)+2/(13)+1/(13)`

Solve : ((-5)/(13) + ((-2))/( 13)) + ((- 3)/(8) + (18)/(20))

Check if lines with direction-cosines : lt (12)/(13) , - (3)/(13) , - (4)/(13) gt , lt (4)/(13) , (12)/(13), (3)/(13) gt , lt (3)/(13) , (4)/(13) , (12)/(13) gt are mutually perpendicular .

Add: 1/13 + 1/13 +1/13

Solve (4/13)^4 . (13/7)^2 . (7/4)^3

4/13+9/13+2/13=-/13

Solve it: 13/5 - 5/13

(-4)/(13)+0=0+(-4)/(13)

4/13 + 9/13 + 2/13 = ?/13

3/13-2/13+5/13 =

Solve 8x+(5)/(2)=(13)/(2)