Solve :
20-9x=11
4(2x+1)=8
5(2x+5)=-15
3(8x+1)=-21

The base of a triangle exceeds the height by 7 centimeters. if the area is 400 square centimeters, find the length of the base and the height of the triangle.

Sally deposited money into a savings account paying 4% simple interest per year.the first year,she earned $75 in interest.how much interest will she earn during the following year?

Tatiana wants to give friendship bracelets to her 32 classmates. she already has 5 bracelets, and she can buy more bracelets in packages of 4. write an inequality to determine the number of packages, p, tatiana could buy to have enough bracelets.