1.49(a+b)^2-16(b-a)^2

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/11/05 22:55:20

1.49(a+b)^2-16(b-a)^2
2.（a-b)(3a+b)^2+(a+3b)^2(b-a)
3.9(a-b)^2+12(a^2-b^2)+4(a+b)^2
先分解因式，再求值
1.25x(0.4-y)^2-10y(y-0.4)^2,其中x=0.04.y=2.4
2.（a^2+b^2)^2-4a^b^2,其中a=3.5,b=1.5

49(a+b)^2-16(b-a)^2
=[7(a+b)+4(b-a)][7(a+b)-4(b-a)]
=(7a+7b+4b-4a)(7a+7b-4b+4a)
=(3a+11b)(3b+11a)
（a-b)(3a+b)^2+(a+3b)^2(b-a)
=(a-b)(3a+b)^2-(a+3b)^2(a-b)
=(a-b)[(3a+b)^2-(a+3b)^2]
=(a-b)(3a+b+a+3b)(3a+b-a-3b)
=(a-b)(4a+4b)(2a-2b)
=8(a-b)^2(a+b)
9(a-b)^2+12(a^2-b^2)+4(a+b)^2
=[3(a-b)]^2+2×3×2(a-b)(a+b)+[2(a+b)]^2
=[3a-3b+2a+2b]^2
=(5a-b)^2
25x(0.4-y)^2-10y(y-0.4)^2,其中x=0.04.y=2.4
=25x(0.4-y)^2-10y(0.4-y)^2
=(25x-10y)(0.4-y)^2
=5(5x-2y)(0.4-y)^2
=5(0.2-4.8)(0.4-2.4)^2
=5*(-4.6)*4
=20*(-4.6)
=-92
（a^2+b^2)^2-4a^2b^2,其中a=3.5,b=1.5
=a^4+b^4+2a^2b^2-4a^2b^2
=a^4+b^4-2a^2b^2
=(a^2-b^2)^2
=(a+b)^2(a-b)^2
=(3.5+1.5)^2(3.5-1.5)^2
=5^2*2^2
=25*4
=100

1.49(a+b)^2-16(b-a)^2 a-b+2b²/a+b 化简：{[(2a-b)/(a+b)]-[b/(a-b)]}÷[(a-2b)/(a+b)] 化简(2a-b/a+b-b/a-b)除以a-2b/a +b 计算：((a+b)(a-b)-(a-b)^2+2b(a-b))/4(a-b) 计算·[(2a+-b)/(a+b)-b/(a+b)]/(a-2b)/(a+b) 化简(2a-b/a+b-b/a-b)除以a-2b/a+b (a-b)(a+b)²-(a+b)(a-b)²+2b(a²+b²) 初二的因式分解：16（a+b)^2+40(a+b)(a-b)+25(a-b)^2 (a/a-b-a/a+b)(a+b)(a-b)/2b (b-a)*(b-a)+(b-a)*2*a等于多少? 化简求值(a-b)/(a+b)+(a+b)/(a-b)-(2a*a-2b*b)/(a*a+b*b)其中a=-2,b=0.