8th Grade Algebra: Radicals
posted by Joy on .
Find each product.
{ this means the square root sign.
1. (3+2{20)(5+3{45)
2. The length and width of the rectangle are x5 and 2x6
a. Write a trinomial that represents that area of the rectangle.
b. What is the smallest integer value of x that will give positive values for the length and the width of the rectangle?

just answered that in
http://www.jiskha.com/display.cgi?id=1232413142 
1. (3+2sqrt 20 )(5+3sqrt 45) ???
use FOIL
15 + 9 sqrt(900) + 10 sqrt(900) + 900
but sqrt 900 = 30
so 15 + 19*30 + 900
2. The length and width of the rectangle are x5 and 2x6
a. Write a trinomial that represents that area of the rectangle.
(x5)(2x6) = 2 x^2 16 x + 30
b. What is the smallest integer value of x that will give positive values for the length and the width of the rectangle?
If x is <5, length is negative
if x < 3, width is negative
so 3 
I multiplied wrong, when I foiled.