Question

zad 1 .wykonaj mnożenie i zredukuj wyrazy podobne :

1) x(5-y)+2-4xy

2) 3x+5y-(x-3)*(y+2)

3) 4x+3(x+y)-4(y-x)

4) -2(x-3y)+(4x-2)-(2-y)

5) 0,5(x+7y)-(0,5x+3)*(1+y)

6) (a+2+6) * (c+1)

7) 6x(x-2)*(4y+1)

8) 4(x-7)*(y-4x+2)

9) 2(x+y+z)*(2+x+3z)

10) -a(b+8)-4a+3ab

11) 4a(5+b)+20a-3ab

zad 2 . rozwiąż równanie

1) 3x(1+x)=3x^2 + 9

2) 2x(2-2x)=16-4x^2

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

4)-7y(y-3)+y^2=-6y-63

duzo pkt dam naj odp.

Answer 1

1) x(5-y)+2-4xy=5x-xy+2-4xy=5x-5xy+2

2.3x+5y-(x-3)*(y+2)=3x+5y-xy+2x-3y-6=5x+2y-xy-6

3) 4x+3(x+y)-4(y-x)=4x+3x+3y-4y+4x=11x+y

4) -2(x-3y)+(4x-2)-(2-y)=-2x+6y+4x-2-2y+y=2x+5y-2

5) 0,5(x+7y)-(0,5x+3)*(1+y)=0,5x+3,5y-0,5x+0,5xy+3+3y=x+6,5y-0,5xy+3

6) (a+2+6) * (c+1)=ac+a+2c+2+6c+6=ac+8c+8

7) 6x(x-2)*(4y+1)=(6x^2-12x)(4y+1)=24x^2y+6x^2-48xy-12x

8) 4(x-7)*(y-4x+2)=(4x-28)(y-4x+2)=4xy-16x^2-8x-28y+112x+56=4xy-16x^2+104x+56

9) 2(x+y+z)*(2+x+3z)=(2x+2y+2z)(y+x+3)=2xy+2x^2+6xz+2y^2+2xy+6yz+2yz+2xz+6z^2=4xy+2x^2+8xz+2y^2+8yz

10) -a(b+8)-4a+3ab=-ab-8a-4a+3ab=2ab-12a

11) 4a(5+b)+20a-3ab=20a+4ab+2a-3ab=22a+ab

 

zad 2

1. 3x(1+x)=3x^2 + 9

3x+3x^2=3x^2+9

3x+3x^2-3x^2=9

3x=9/:3

x=3

 

2.2x(2-2x)=16-4x^2

4x-4x^2=16-4x^2

4x-4x^2+4x^2=16

4x=16/:4

x=4

 

3. -2(5x^2 +2)=5x(4-2x)

-10x^2-4=20x-10x^2

-10x^2+10x^2-20x=4

-20x=4/:(-20)

x=-0,2

 

4.

-7y(y-3)+y^2=-6y-63

-7y^2-21y+y^2=-6y-63

7y^2-21y+y^2+6y=63

-6y^2+15y+63

3y(2y+5)=63

3y=63/:3 lub 2y+5=63

y=21 lub 2y=58/:2

y=21 lub y=29