Which statement is true about the polynomial –3x4y3 + 8xy5 – 3 + 18x3y4 – 3xy5 after it has been fully simplified?

What is the total surface area of this square pyramid?

Can some one me with these questions

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?