This is a supplementary angle (or whatever the term was for two or more angles that add together to get 180 degrees). There is a total of 7x and 5 degrees. So you would set up the equation 180= 7x+5. Use the properties of equality and subtract 5 from both sides getting 175= 7x. Use the division property of equality to isolate the variable. Divide by 7 to get 25=x. Now just substitute for x in 5x+5 getting 125+5= 130. Sorry if I did a bad job at explaining
