(DUZO PKT) Zad : 5,6,7,8 | PLS potrzebuje na jutro ! Jstm slaby z matmy :( pomozecie ? daje naj!

5) a)5x+7y-8y-8-3x+3y ⇒ 2x+2y-8       2×0,5 + 2×0,25 - 8 = 1 + 0,5 - 8 =  -6,5 b)2a-3b+4c²-7a+9b-3c² ⇒ -5a+6b+c²      -5×(-3) + 6×(-1/6) + 2²  = 15 - 1 + 4 = 17 c)4(y-3)-3(x+1) ⇒ 4y - 12 -3x -3 = -3x +4y -15      -3×4 + 4×2 - 15 = -12 + 8 - 15 = -19 d)(5x+7)-8(y+1)+3(x-y) ⇒ 5x + 7- 8y-8 + 3x - 3y = 8x - 1 -11y = 8x - 11y -1      8×(1/2) - 11×(1/4) - 1 = 4 - (11/4) - 1 = 3 - (11/4) = 1/4  6) 0,40a+0,80b lub (4/10)a + (8/10)b 7) a)(13x+2y+2)-(24-7y+27) ⇒ 13x+2y+2-24+7y-27 = 13x+9y-49 b)-(2a+1)+(4a-5b+8)-2b ⇒ -2a-1+4a-5b+8 = 2a-5b+7 c)3(2m-7n)-6(m-5n)-2(-m+n) ⇒ 6m-21n-6m+30n+2m-2n =2m+7n 8) a)12y -4x³+6x²y ⇒ x²(12y-4x+6y)⇒x²(18y-4x) b)5a²-10b+15 ⇒ 5(a²-2b+3) c)21x²-14xy³+7 ⇒ 7(x(3x+2y³)+1)