Toán Lớp 8: 1. (3x-1)(2x+3)-(x-5)(6x-1)-38x 2. (5x-2)(x+1)-(x-3)(5x+1)-17(x-2) CẢM ƠN AH

Question

Toán Lớp 8:  1. (3x-1)(2x+3)-(x-5)(6x-1)-38x 2. (5x-2)(x+1)-(x-3)(5x+1)-17(x-2)       CẢM ƠN AH

giangnguyen33 · Answer

Giải đáp:   1)-8   2)35   Lời giải và giải thích chi tiết:   1)(3x-1)(2x+3)-(x-5)(6x-1)-38x   =6x&sup2;+9x-2x-3-(6x&sup2;-x-30x+5)-38x   =6x&sup2;+9x-2x-3-6x&sup2;+x+30x-5-38x   =(6x&sup2;-6x&sup2;)+(9x-2x+x+30x-38x)+(-3-5)   =-8   2)(5x-2)(x+1)-(x-3)(5x+1)-17(x-2)   =5x&sup2;+5x-2x-2-(5x&sup2;+x-15x-3)-17x+34   =5x&sup2;+5x-2x-2-5x&sup2;-x+15x+3-17x+34   =(5x&sup2;-5x&sup2;)+(5x-2x-x+15x-17x)+(-2+3+34)   =35

diemchau · Answer

Giải đáp:       Lời giải và giải thích chi tiết:    text{@Terminators}   1. (3x-1)(2x+3)-(x-5)(6x-1)-38x   = 6x^2 + 7x - 3 - 6x^2 + 31x - 5 - 38x   = (6x^2-6x^2) + (38x-31x-7x) - (5+3)   = -8   2. (5x-2)(x+1)-(x-3)(5x+1)-17(x-2)   = 5x^2 + 3x - 2 - 5x^2 + 14x + 3 - 17x + 34   = (5x^2-5x^2)+(17x-14x-3x)+(34+3-2)   = 35