Find 15/4+(−4 1/3). Write your answer as a fraction in simplest form.

Use sigma notation to represent the following series for 9 terms.

Find the arc length of the semicircle. 7the grade

Triangles abc and dfg are given. find the lengths of all other sides of these triangles if: b ∠a≅∠d, ab·dg=ac·df, ac=7 cm, bc=15 cm, fg=20 cm, and df-ab=3 cm.