someone please help I don't understand what to do for the table !!! I'm not that good with fractions

Nick estimated that 5/8+4/7 is about 2.explain how you know his estimate is not reasonable plz and fast i will give 50 points

Rhombus adef is inscribed into a triangle abc so that they share angle a and the vertex e lies on the side bc . what is the length of the side of the rhombus if ab=c, and ac=b.

Ntriangle abc, m∠a = 35° and m∠b = 40°, and a=9. which equation should you solve to find b?