If our consecutive odd integers were 1, 3, 5, and 7, for example, and x represents the number 1, then x+2 would represent the number 3, x+4 would represent the number 5, and x+6 would represent the number 7. So the expressions for the integers need to be added together to equal 280. x+(x+2)+(x+4)+(x+6) = 280. You don't really need the parenthesis but I put them there so you could see how the equation is set up using them. That simplifies down to 4x + 12 = 280. Then 4x = 268 and x = 67. 67 is the smallest odd number of the bunch, then x+2=69, x+4=71, and x+6=73. There you go!
