Question

ajutati maaaaa ex 9 ......​

Answer 1

Răspuns:

a) 7x(x+2) + (x+2)² - 3(x+2) = (x+2)(8x-1)

b) (y+3)(y+2) + 4(y+3)² - 4y(y+3) = (y+3)(y+14)

c) (y+5)(3y-7) - (y+5)(4y-2) + 3(y+5) = (y+5)(-y-2)

d) (3x-5)² - (3x-5)(2x-1) + 6x(3x-5) = (3x-5)(7x-4)

e) (5x-4)(3x-2)² - (3x-2)² + 2(x+4)(3x-2)² = (3x-2)²(7x+3)

f) (4y-5z)(2y+z) - (3y-z)(5z-4y) + (5z-4y)² = (5z-4y)(5z-9y)

Explicație:

a)

7x(x+2) + (x+2)² - 3(x+2) =

= (x+2)(7x + x+2 - 3)

= (x+2)(8x-1)

b)

(y+3)(y+2) + 4(y+3)² - 4y(y+3) =

= (y+3)[y+2+4(y+3)-4y]

= (y+3)(y+2+4y+12-4y)

= (y+3)(y+14)

c)

(y+5)(3y-7) - (y+5)(4y-2) + 3(y+5) =

= (y+5)(3y-7-4y+2+3)

= (y+5)(-y-2)

d)

(3x-5)² - (3x-5)(2x-1) + 6x(3x-5) =

= (3x-5)(3x-5 - 2x+1 + 6x)

= (3x-5)(7x-4)

e)

(5x-4)(3x-2)² - (3x-2)² + 2(x+4)(3x-2)² =

= (3x-2)²[(5x-4 - 1 + 2(x+4)]

= (3x-2)²(5x-4 - 1 + 2x+8)

= (3x-2)²(7x+3)

f)

(4y-5z)(2y+z) - (3y-z)(5z-4y) + (5z-4y)²

= (5z-4y)(-2y-z -3y+z +5z-4y)

= (5z-4y)(-9y+5z)

= (5z-4y)(5z-9y)