-5(x-2y)^20 -4(5x-13y)^39 +3(5x-13y)^39 -20(x-2y)^20 其中 x=5 y=2

4x+2y-5x-y 因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) 化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90) (1)x^2*x^8+x^13/x^3 (2)a^19/a^12/a^3 (3) (x-2y)^5/(2y-x)^3 (4)(x-y)^5/(x-y) (5)(x-y)^6/(y-x)^4 1.分解因式：4x³-31x+152.把12x²+14xy-20y²+20x-11y+33.x³+6x²+11x+64.x⁴+2x³-9x²-2x+85.x²+xy-6y²+x+13y-66.x³+5x²+3x-9 4(x+y)^2-20(x+y-1)+5因式分解 化简(4x-2y)-[5x-(8y-2x-x-y)]+x 化简(4x-2y)-﹛5x-[8y-2x-(x+y)]-x﹜ 初二上学期方程题 4x+y=5 5x+4y=63x-2y=1 2x+3y=13x-2y=7 7x+5y=32x+3y=17 2x-y=-4x+5y=6 2x+y=23x-6y=4 3x+2y=52x+y=73x-4y=53x+y=1x-2y=-1x+y=42x+3y=92x-3y=74x+5y=3x+y=20004x+6y=90003x+5y=113x-2y=42x+3y=215x-2y=5x+y=54x+3y=182x+3y=16x+4y=132x+3y=40x 5/4(x+y)(-x-y)^3*[-4/3(x-y)]*[-3/5(y-x)^2] 5x(x-y)-(4Y-x)^2因式分解 [(2x+y)^2-(x+y)(x-4y)-5y^2]除以2x (2x-y)(3x-4y)-2(x-y)(2x-5y)简便运算 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 x*x+2x+y*y-4y+5=0 x= y= 5x^3y(x-y)^3-10x^4y^3(y-x)^2因式分解