Wykonaj redukcje wyrazow p;odobnych i oblicz wartosci liczbowe wyrazen:

a). 2[4x - (4y + 3x)] - 4[3x - (2x - 3y)]=


dla x = -3,5 i y = 5/6

b). a - 2(b - 1) + 2[ - 5(a + 1) - 0,5a] + 2b=


dla a = 4/5 i b = 1/4

c). 3x - 2(- 5 + y) - 5[- 3x + 2(y - 1)] - 10(5y - 4)=

dla x = -1/3 i y = -4

3

Odpowiedzi

2010-04-02T09:19:22+02:00
A)2[4x-4y-3x]-4[3x-2x+3y)=8x-8y-6x-12x+8x-12y=-2x-20y
-2*-3,5-20*5/6=7-16i2/3=9i 2/3
b)a-2b+2+2-5a-5-0,5a+2b=4,5a-1
4,5*4/5-1=3,6-1=2,6
c)3x+10-2y-5[-3x+2y-2]-50y+40=3x+10-2y+15x-10y+10-50y+40=
=18x-62y+60
18*-1/3-62*-4+60=-6+248+60=302
  • Użytkownik Zadane
2010-04-02T09:23:57+02:00
a) 2[4x - (4y + 3x)] - 4[3x - (2x - 3y)]= 2(4x - 4y - 3x) - 4(3x-2x+3y) =
= 2(x - 4y) - 4( x + 3y) = 2x - 8y - 4x - 12y = -2x - 20y


dla x = -3,5 i y = 5/6

-2(-3,5) - 20(5/6) = 7 - 100/6 = 7 - 16 ⅔ = -9 ⅔

b) a - 2(b - 1) + 2[ - 5(a + 1) - 0,5a] + 2b= a - 2b + 2 + 2[-5a - 5 - 0,5a] +2b =
a - 2b + 2 - 10a -10 - a + 2b = -10a -8

dla a = 4/5 i b = 1/4 [nie wiem po co b, skoro się skróciło]

-10 *4/5 -8 = -b -b = -16

c) 3x - 2(- 5 + y) - 5[- 3x + 2(y - 1)] - 10(5y - 4)=
= 3x + 10 - 2y - 5[-3x + 2y -2] - 50y + 40 = 3x -52y +50 +15x - 10y +10 =
18x - 62y +60

dla x = -1/3 i y = -4

18(-1/3) - 62(-4) +60 = -6 + 248 +60 = 302
2010-04-02T09:32:51+02:00
A). 2[4x - (4y + 3x)] - 4[3x - (2x - 3y)] = 2 * (4x - 4y - 3x) - 4 * (3x - 2x + 3y) = 2 * (x - 4y) - 4 * (x + 3y) = 2x - 4y - 4x - 12y = - 2x - 16y =
- 2 * (-3,5) - 16 * 5/6 = 7 - 13 1/3 = - 6 1/3

b). a - 2(b - 1) + 2[ - 5(a + 1) - 0,5a] + 2b = a - 2b + 2 + 2 * (- 5a - 5 - 0,5a) + 2b = a - 2b + 2 * (- 5,5a - 5) + 2b = a - 2b - 11a - 10 + 2b = -10a - 10 = - 10 * 4/5 - 10 = - 8 - 10 = - 18

c). 3x - 2(- 5 + y) - 5[- 3x + 2(y - 1)] - 10(5y - 4) = 3x + 10 - 2y - 5 * (- 3x + 2y - 2) - 50y + 40 = 3x + 10 - 2y + 15x - 10y + 10 - 50y + 40 = 18x + 60 - 62y = 18 * - 1/3 + 60 - 62 * - 4 = - 6 + 60 + 248 = 302