Find the nonpermissible replacement for 'n' in this expression (-8)/(5n)

Zoe placed colored blocks on a scale in science class. each block weighed 0.8 ounces. the total weight of all the colored blocks was 12.8 ounces. how many blocks did zoe place on the scale? write and solve an equation to find the answer.

Find the value of tan theta if sin theta = 12/13 and theta is in quadrant 2

The center of the circumscribed circle lies on line segment and the longest side of the triangle is equal to the of the circle.