The ones digit of a two digit number is one less than the tens digit. one-half of the sum of the ones digit and double the tens digit is 13. find the number and show work

 hd the number. h-1=d, and 1/2*(d+2h) simple. h is 9 and d is 8.  So, answer is 98. 

Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm