Write a fraction that is a multiple of 4/5

What is the missing constant term in the perfect square that starts with x^2 -20x

Jake bakes and sell apple pies. he sells each pie for $5.75 . the materials to make the pies cost $40. the boxes jake puts the pies in cost & 12.50 total. how many pies does jake need to sell to earn a profit of $50

Simplify the algebraic expression 8y-2(y+4)