Question

Doprowadz wyrażenia do najprostrzej postaci

1) [-4(x2-10x-7)+(2x-3).(3x-2)](2x-1)

2)[2(x2-5x-3)-3(x-2).(x+4)](x=3)

3)2(-3a-4b)-3(a+2b)+4(2a+3b) dla a=-3 dla b+2

plisss szybkaodp daje naj.

Answer 1

Doprowadz wyrażenia do najprostrzej postaci

1) [-4(x2-10x-7)+(2x-3).(3x-2)](2x-1)=

= [-4x² +40x +28 + 6x²-4x -9x +6 ]*(2x -1) =

= [ 2x² + 27x +34 ]*(2x -1) =

= 4x³ -2x² +54x² -27x  +68x - 34 =

= 4x³ +52x²41x -34

 

2)[2(x2-5x-3)-3(x-2).(x+4)](x=3)     co tu ma być  ?????(x =3)

= [2x² -10x -6 -3(x² +4x -2x -8)]( x =3)

= [ 2x² -10x -6 -3x²- 6x +24 ] ( x =3) =

= [ -x²  -16x  +18 ]( x +3) =

= [  -x³ -3x² -16x² -48x +18x +54 ] =

=  -x³ - 19x² - 30x +54

 

 

3)2(-3a-4b)-3(a+2b)+4(2a+3b)   dla a=-3  dla b+2

=  -6a -8b - 3a -6b +8a +12b =

= -a -2b =

= -(-3) - 2*2 =

= 3  -4 =

= -1

Answer 2

1) = [(-4x^{2}+40x+28)+(6x^{2}-4x-9x+6)] (2x-1) = [-4x^{2} 40x +28 +6x^{2} -4x-9x+6) (2x-1)= [2x^{2} +27x+34] (2x-1) = 4x^{3}-2x^{2}+54x^{2}-27x+68x-34=4x^{3}+52x^{2}+41x-34

 

2) = [2x^{2}-10x-6)-3(x^{2}+4x-2x-8)] (x+3)= [2x^{2}-10x-6-3x^{2}-12x+8x+24](x+3)= (-x^{2}-14x+18)(x+3) = -x^{3}-14x^{2}+18x-3x^{2}-42x+54= -x^{3}-17x^{2}-24x+54

 

3) = -6a-8b-3a -6b+8a+12b= -a+2b= -(-3) -2(2)= 3-4= -1