(5x+7y-3)×(5x-7y+3)=()
2个回答
原式=[5x+(7y-3)][5x-(7y-3)]=25x2-(7y-3)2=25x2-(49y2-42y+9)
=25x2-49y2+42y-9
相关问题
计算:[5X+7Y-3][5X+3-7Y]
(5x+7y-3)(5x-7y+3)等于多少,
送分的5x+y=7,3x-y=1 4x-3y=5,4x+6y=14 6x+7y=5,6x-7y=190.5x-3y=-1
2x-y=5 7x-3y=-5
2x+3Y=-5 x+3y=-7 x-y=3
2x-3y-2=0 5x+3y=18 2x-3y=7 (2x-3y+5)/7+2y=9 2x-3y=3 6x+5y=35
z+y=3x,3x-9=y-1,5y-5=3x-7
(3y+5+6x)-(3y+5x-7) 简化
计算 3(2x-7y)(7y+2x)+(4x+5y)(-5y-4x)
3x-2y=7 3x-y=5