Help what is the m and b ?

Grandma made an apple pie. josh and his brother joe finished 4/5 of it. then 3 friends came over and shared the left over. how much pie did each friend eat

Answer this question, only if you know the answer. 30 points and brainliest!

Jonathan pays $1.90 per pound for potatoes. he buys 8.3 pounds of potatoes. he determines that he will pay $15.77, before tax, for the potatoes. which best describes the reasonableness of jonathan’s solution? jonathan’s answer is reasonable because there are two decimal places in the factors and two in the product. jonathan’s answer is unreasonable because there are three decimal places in the factors and two in the product. jonathan’s answer is reasonable because is 16, and 16 is close to 15.77. jonathan’s answer is unreasonable because is 8, and 8 is not very close to 15.77.