Question

efetue a) (4x-9)^2
b)(5x+y)(5x-y)
c)(3a+8b)^2
d)(x-2/3)^2

Answer 1

a)(4x-9)²
(4x-9)(4x-9)
16x²-36x-36x+81
16x²-72x+81

B) (5x+y)(5x-y)
25x²-5xy+5xy-y²
25x²-y²


C) (3a+8b)²
(3a+8b)(3a+8b)
9a²+24ab+24ab+64b²
9a²+48ab+64b²



D) (x-2/3)²
(x-2/3)(x-2/3)
x²-2x-2x+4
_ _ _
3 3 9
9x²-6x-6x+4
9x²-12x+4

Answer 2

a) (4x-9)^2
(4x -9) . (4x -9)
a) 16x² -36x -36x +81
16x² -72x +81


b) (5x + y). (5x -y)
25x² -5xy +5xy -y²         elimina -5xy +5xy, pois são iguais e sinais diferentes
25x² -y²


c) (3a + 8b)²
(3a +8b) . (3a +8b)
9a² +24ab +24ab +64b²
9a² +48ab +64b²


d) (x-2/3)²
(x- 2/3) . (x- 2/3)
x² - 2x/3 -  2x/3 + 4/9
x² -4x/3 +4/9