Corinne is 6 years younger than her brother. which of the following expressions shows the sum of their ages if b represents corinne's brother's age?

From the given conditions above, if Corrine's brother's age is b, hers would be b - 6 given that she is 6 year younger. Adding b with b - 6 will give 2b - 6. Thus, the expression that shows the sum of their ages is 2b - 6. 

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