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解方程:0.25x-4分之1=x+0.5 计算:-2³-(1-0...

(1) 两边开方,得2(x - 1) = 3(x - 5)或2(x - 1) = -3(x - 5), 分别得x = 13和x = 17/5 (2) 只好套公式: x = (7 ± √41)/2 (3) (x - 2)(x + 1) = 0 x = 2, x = -1

(-b±√(b²-4ac))/2a a=1 b=-4 c=-1 (-b±√(b²-4ac))/2a =(4±√(16+4))/2 =(4±2*√5))/2 =2±√5

原方程为x3-4x2+x+5=0,令f(x)=x3-4x2+x+5.∵f(-1)=-1,f(0)=5,f(-1)·f(0)<0,∴函数f(x)在(-1,0)内有零点x0.  取(-1,0)作为计算的初始区间用二分法逐步计算,列表如下  端点或中点横坐标 端点或中点的函数值...

X+0.5XY+0.25XY²+0.125XY³ =0.125X (2+Y )(4+Y²)

x²+x-1=0 (x²+x+1/4)-1/4-1=0 (x+1/2)²-5/4=0 (x+1/2)²=5/4 x+1/2=±(√5)/2 x=±(√5)/2-1/2 x=[±(√5)-1]/2 x1=[(√5)-1]/2,x2=-[(√5)+1]/2

先用二项式定理把两边展开: 1+5x+10x²+10x³+5(x^4)+(x^5)=1-5x+10x²-10x³+5(x^4)-(x^5) 移项,合并,整理可得: 10x+20x³+2(x^5)=0 x[(x^4)+10x²+5]=0 x[(x²+5)²-20]=0 x[x²+5+2√5][x²+5-2√5]...

(x-1)²-4=5 (x-1)²=9 x-1=3 x-1=-3 x=4 x=-2 (x-0.6)³=0.064 x-0.6=0.4 x=1 -100(x-1)²=(-4)³ (x-1)²=64/100 x-1=8/10 x-1= -8/10 x=9/5 x=1/5

(1+x²)y dx-(2-y)x dy=0 (1+x²)y dx =(2-y)x dy 【(1+x²)/x】dx =【(2-y)/y】dy (x+1/x)dx=(-1+2/y)dy d(0.5x²+Inx)= d(-y+2Iny) 0.5x²+Inx = -y+2Iny+C 0.5x²+y=In(C y²/x) C y²...

解: 方程有实根,判别式△≥0 [-2(m+1)]²-4(m²+5)≥0 解得m≥2 1. 由韦达定理得:x₁+x₂=2(m+1),x₁x₂=m²+5 (x₁-1)(x₂-1)=28 x₁x₂-(x₁+x₂)+1=28 m²+5-2(m+1)+1=28...

(1)解:x ² - 2 x - 5 = 0 x ² - 2 x + 1 - 1 - 5 = 0 (x - 1)² - 6 = 0 (x - 1)² = 6 x - 1 = ± √6 x = ± √6 + 1 x1 = √6 + 1 x2 = - √6 + 1 (2)解:3 x ² + 2 x - 1 = 0 x ² + (2 / 3)x - 1 / 3 = 0 。

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