Need some help on homework.?

Question

PLEASE PLEASE HELP ME !!!

1.The product of a number is 21 is decreased by 102. The result is equal to the product of the number and 11, increased by 8. What is the number?

2.Find the area of this trapezoid. Dimensions are in inches.
( If you cant see the numbers in the pictures, 7, 10, and 8)
In the picture there is a dotted line! the 7 is on it.
http://img.photobucket.com/albums/v631/die4tacops/untitled.jpg


3.Find m.
(The numbers are 13, 9 , and m
http://img.photobucket.com/albums/v631/die4tacops/untitled1.jpg

Answer 1

1. 21x - 102 = 11x + 8 Solve for x

2. ((2 x 7)/2) + (8 x 7)

3. c^2=a^2+b^2

13^2= 9^2 + b^2

b=sqrt [ 9^2 - 13^2]

Answer 2

3. m=15.81