Question

resolva as equaçoes sendo u=r:
a (x+3)²-(x-3)²=3
b (2x-10)²-(2x+1)²=0

Answer 1

a
( x + 3)²  - ( x - 3)² = 3

[ (x)² + 2 . x . 3  + (3)² ]  - [ ( (x)²  - 2 . x . 3 + (3)² ]  = 3
( x² + 6x + 9 ) - ( x² - 6x + 9) = 3
x² + 6x + 9 - x² + 6x - 9 - 3 = 0
12x - 3 = 0
12x = 3
x = 3/12 = 1/4 ****

b
( 2x - 10)²  - ( 2x + 1)² = 0
[ ( 2x)²  - 2 . 2x . 10  + (10)²]  - [  (2x)² + 2 . 2x . 1  +(1)² ]
( 4x² - 40x + 100 ) - ( 4x² + 4x + 1 ] = 0
4x² - 40x + 100 - 4x² - 4x - 1 = 0
- 44x + 99 = 0
44x - 99 = 0
44x = 99
x = 99/44 = 9/4 ***