4 2x>7x 3 4x 5
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x+2x+x/2=3x+x/2=(6/2)x+x/2=7/2x42-25=17所以原式=7/2x+17
X加8分之7X等于428X+7X=33615X=336X=22.4
7x-14=5x+97x-5x=9+142x=23x=11.53x-12=5x-205x-3x=20-122x=8x=456x=42(x+2)56x=42x+42*256x-42x=8414x=84x
|x-1|+|x-10|表示数轴上x到1的距离+x到10的距离.显然最小值是9,此时x只要在1到10之间就好.类似的,|x-2|+|x-9|的最小值是7,此时x在2到9之间就好.|x-3|+|x-8|
-7
x(1+2+...+9)=x(9-8-7-...-1)x=0记得采纳啊
1、(0.3+x)*2=80.6+2x=82x=7.4x=3.72、7+5x=425x=35x=73、1.3x-x=18.60.3x=18.6x=62
(x+7)(x+5)-(x+1)(x+5)=42(x+5)[(x+7)-(x+1)]=426(x+5)=42x+5=7x=2
提取公因式(x+5)6=42(x+5)=7所以x=2
(x/2)+(x/6)+(x/12)+(x/20)+(x/30)+(x/42)=x/(1*2)+x/(2*3)+x/(3*4)+x/(4*5)+x/(5*6)+x/(6*7)=x-x/2+x/2-x/
(x+7)(x+5)-(x-1)(x+1)(x+5)=42(x+7)(x+5)-(x²-1)(x+5)=42[(x+7)-(x²-1)](x+5)=42(-x²+x+8)
应该是-2x²,不是-3x²3x²-x=1原式=9x^4-3x³+15x³-5x²+3x²-7x+2001=3x²(3x
(0.3+x)*2=80.3+x=8÷20.3+x=4x=4-0.3x=3.77+5x=425x=42-75x=35x=35÷5x=71.3x-x=18.60.3x=18.6x=18.6÷0.3x=6
x-42%x-42%*7/5=42%x*7/5-2x-0.42x-0.588=0.588x-20.588x-x+0.42x=2-0.5880.008x=1.412x=176.5
(x+7)(x+5)-(x+1)(x+5)=42(x+5)(x+7-x-1)=426(x+5)=42x+5=7x=2
#includesintjiesheng(intn)//用于计算阶乘如:3!{if(n=1)rerunn;returnn*hh(n-1)}doubledigui(intn,intx)//用以计算y=x
x+7/8x=42x*15/8=42x=42*8/15x=112/5
5x÷8-3x=405x-24x=320-19x=320x=-320/197x-8=42+3x7x-3x=42+84x=40x=109x+7-3x=9x-39x-3x-9x=-3-7-3x=-10x=
1.分解因式X(X-7)²+6X-42X(X-7)²+6X-42=X(X-7)²+6(X-7)(提公因式)=(X-7)[X(X-7)+6]=(X-7)[X²-7