Decide which story can be represented by the system of equations below.
y=x+6.5y=x+6.5
x+y=19.5x+y=19.5
a. Rosa has 6.5 times more blue fabric than red fabric. She has a total of 19.5 yards of fabric.
b. Ryan's shoe size is 6.5 sizes larger than his little brother, Harrison. Ryan and his sister, Sasha's, shoe sizes add up to 19.5.
c. Yandel has 6.5 more pieces of pizza than his dad. Together, he and his dad have 19.5 pieces of pizza.