The Cheer Club is making a banner for your school using the design shown. The area of the yellow portion is 1 ft2. The expression 8z−1 represents the area in square feet of the blue material in the banner. Evaluate the expression for z=9 to find the area of the blue material. When the length z is 9 feet, the blue area is ft2?

Long division setup showing an incomplete calculation. 12 is in the divisor, 6839 is in the dividend, and 5 hundreds and 6 tens is written in the quotient. 6000 is subtracted from 6839 to give 839. an unknown value represented by a box is being subtracted from 839. what number should be placed in the box to complete the division calculation?