Question

Mam zadanie z matematyki pomóżcie proszę:

zad.1.Wykonaj działania i redukcję wyrażeń podobnyh:

a) -(5x-4)+(6x+8)=

b) 2/3 razy (15x-6)=

c) 7x razy(1/7x+4)-(27x-9):3=

d) (4x-2) razy (6+2x)=

e) (7x-2)(x+1)-(1-x)(x+3)=

f) (x-1) do kwadratu+(2x+5) do kwadratu-(x+3)(x-3)=

dam naj. ale pomóżcie :))

Answer 1

a) =-5x+4+6x+8=x+12

 

b) = 10x-4

 

c) = x+ 4/7 -3x+3 = -2x + 25/7

 

d) = 24x +8x^2-12-4x = 8x^2 + 20x -12

 

e) = 7x^2+7x-2x-2 -x-3+x^2+3x = 8x^2+7x-5

 

f) =x^2-2x+1 +4x^2+20x+25 - x^2+9 = 4x^2+18x+35

Answer 2

 Wzory skróconego mnożenia:

(a+b)²=a²+2ab+b² - kwadrat sumy;

(a-b)²=a²-2ab+b² - kwadrat różnicy;

a²-b²=(a-b)(a+b) - różnica kwadratów;

==============================================

a) -(5x-4)+(6x+8)=

=-5x+4+6x+8=

=x+12

------------------------------------

b) 2/3 * (15x-6)=

=2*15x/3 -2*6/3=

=2*5x-2*2=

=10x-4

------------------------------------

c) 7x *(1/7x+4)-(27x-9):3=

=7x*x/7 + 7x*4 - (27x:3 - 9:3)=

=x²+28x-9x+3=

=x²+19x+3

------------------------------------

d) (4x-2)*(6+2x)=

=4x*6-2*6+4x*2x-2*2x=

=24x-12+8x²-4x=

=8x²+20x-12

------------------------------------

e) (7x-2)(x+1)-(1-x)(x+3)=

=7x*x-2*x+7x*1-2*1 - [1*x-x*x+3*1-x*3]=

=7x²-2x+7x-2 - [x-x²+3-3x]=

=7x²+5x-2 - [-x²-2x+3]=

=7x²+5x-2+x²+2x-3=

=8x²+7x-5

------------------------------------

f) (x-1)²+(2x+5)²-(x+3)(x-3)=

=x²-2x+1 + 4x²+20x+25 - [x²-9]=

=5x²+18x+26 - x²+9=

=4x²+18x+35