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你们。网址又没用 说清楚些
你们。网址又没用 说清楚些
P15:

4√√√6/3√17/7√6

II解决方案:简化为:2√2a的+6√2A-3√ 2a的= 5√2a的将是一个= 6代入5√12 = 10√3
/> 3,(1)OA10 =√(√9)2 12 =√10
(2)S12 = 1/4 S22 = 2/4 = 1/2 S32 = 3/4型Sn2 =π/ 4

S12 + S22 + S32 + ... + S102 = 1/4(1 +2 +3 + ... +10)= 55/4

(1)小明(2)的平方根的数量是大于零
五(1)= -1(2)X1 = 0的2倍= 2(3)X1 = - √6-1的2倍=√6-1

( 4)X1 =√3-1 X2 = - √3-1(5)△= B2-4AC = 4-8 +4 M> 0因此m> 1

六(1)替换成

(2)假设= X2 = Y2-Y-6 = 0

(Y-3)第(y +2)= 0 Y1 = Y2 = -2

因为x2> 0 Y> 0 Y = X2 = 3 =±√3

(3)畸形:(X2-1)2 - (X-1 3)= 0假设为y = 2倍-1
/> Y2-γ3 = 0,Y1 = Y2 = 3

的2倍,1 = 1×=±√2 X2-1 = 3×=±2

P17:

1-2日

两个1 ×2 - 4×4 = 1(1)(3)= 0 2. △=β2-4ac时= 4> 0为3x2-2倍= 0

(2)2 = 1 X1 = 3×2 = 1×=-B±√β2-4ac时/ 2A(3倍2)×= 0 的x 2 =±1溶液X1 = 0的2倍= 2/3 X1 = 0的2倍= 2/3

X1 = 3×2 = 1

3. (2×3)2 - (2×3)= 0 4×2 - 14倍12 = 0

(2×3)(2×-3-1)= 0 2×2 7倍6 = 0
X1 = 3/2 X2 = 2(2X-3)(X-2)

X1 = 3/2 X2 = 2

4. (2X-3)2 = 32(2 +3)2 4X2-12X + 9 = 36x2个+108所述+81

(2X-3)+3(2 +3)] [( 2X-3)-3(2 +3)] = 0 32X2 +120×72 = 0

(8X +6)(-4-12)= 0 4X2 +15所述+9 =

X1 = -3 / 4 X2 = -3 X1 = -3 / 4 X2 = -3

错误应该是在c = -2√2△= B2-4AC = 64> 0

∵=√2 = 4√3 = -2√2

∴所述=-b的±√B2-4AC / 2A

X1 = -2√6 +4√2 X2 = -2√6-4√2

2. 1Δ=(2M +1)2-4(M-2)(M-2)=4平方米+4米+1-4平方米+16 M -16 = 20M-15时,三角洲> 0时,两个不相等的实数根20米-15>0米中>42分之3三角洲= 0有两个相等的实数根20M-15 = 0M =3/43Δ. 这根电线的长度切成两部分,分别是4厘米,16厘米个.
(2)面积?两个正方形和不能等于12平方厘米.
原因:让该地区的两个广场和?
= X2 +(1-X)2 = 2(X-5/2)2 +25 / 2
∵ y以Y,= 12> 0∴X = 5/2,y最小值= 12.5> 12,该区
∴两方不能等于12平方厘米的. />(溶液:(1)2 +(5)2 = 12 />简化为2x2的10倍13 = 0,
∵△=(-10)2 - 4×2×13 -4 0的2倍,2.5倍+1 = 0 BR p> X1 = 1/2×2 = 2×=-B±√B2-4AC / 2A(X-1.25)2 = 9/16

X1 = 1/2 X2 = 2×1.25 =±3/4

X1 = 1/2×2 = 2
二,溶液:x = 2时4-4P + 3代入= 0,所以P = 7/4

2到p = 7/4代入x2-7/2x +3 = 0解X1 = X2 = 1.5的另一根1.5 BR />三,解决方案:让增长率在x

30000(1 + X)2 = 36300

解决方案X1 = 0.1 X2 = -2.1(舍去)

增长率为10%

总水净化(1 +0.1):30000 +30000 +30000(1 +0.1)=99300公斤
BR /> IV的解决方案:让售价利润640万元

(X-8)[200-2 * 10 *(X-10)] = 640

640元五,1米(90米)/ 100多付25-10 = 15米(80米)/ 100 = 15解决方案,M = 50

P21:

解决方案:∵OA = OD∴∠OAD =∠ODA = 18°∴∠AOD = 144°

∵AB = BC = CD∴∠AOB =∠ BOC =∠COD = 48°

∵OC = OD∴∠OCD =∠ODC = 66°

二,解决方案:我们可以看到标题,CD BR p>圆直径相交的E设AB和CD,CD平分AB的垂直连接点E OA

OA = 25厘米,AE = AB / 2 = 24

OE = OA2-AE2 = 7厘米

CE =√OC-OE = 18厘米DE = CD-CE = 32厘米

AC =√AE2 + CE2 = 30厘米

AD =√AE2 + DE2 = 40

三种溶液:BE = 2.5

BE BC圆B外

四∵AB是直径∴∠C = 90°,∵∠ABC = 2∠A∴∠A = 30°,∠ABC = 60°

2∵M小弧∴ ∠CBM,中点的AC =∠反弹道导弹= 30°∴AD = BD,BD = 2CD∴AD = 2CD



法A:

因为AD / / BC∠EAD =∠ABC,∠DAG =∠AGB

因为AB = AG,∠ABC =∠AGB

所以∠EAD = ∠DAG 连接EF,FG

已经知道通过法律∠EAD =∠DAG

和AF = AF,AE = AG
可以得到△AFE全等于△AFG

EF = FG

弧和弧EF = FG(在同一圈弧对应相同的和弦相等)

6(1)连接OC

∵DC切

∴∠OCD = 90°
∵∠CAD =∠OAB

∴∠CAD =∠ACD

∴Δ型DAC等腰△


∵∴DC = DA

(2)DA平行移动,∠CAD =∠ACD.

∴△ADC换另一侧△

∴DC = DA

(3),然后直线DA水平移动⊙ō

∵的∠DCA =∠DCA,∠DAC =∠DAC (图平行线定理表明)

∴∠CAD =∠ACD

∴DC = DA

注:√根强调作为一个整体:一小部分的根...

P23:

,弧BC =120π×20÷180 =40/3π弧DE =:PI(20-15)* 120 =10/3π
2,S =1/3π(R2-R2)=1/3π*(R + R)(RR)=1/3π* 25 * 15 =125πcm2
>
120π* 1 +120π* 1÷180 = 4/3π

,1,3大小:A2-PI(A / 2)2 =(1-π/ 4)A2 2面积:a2-1/2π(A / 2)2 =(1-π/ 8)A2

4区:90πa2/360×2-A2 =(π/ 2 -1)A2

4比1战平,两个圆圈,两条切线外内

半径的圆B:10 +4 = 14厘米10-4 = 6厘米

五等于我们可以看到标题:AB = AC =铁= FC,∠ACB =∠FCE∴一致的

∠ACE =∠FCB∴△BCF全等△ECA∴AE = BF

四边形ABFE共四个△,他们等待年底的轮廓,所以SABFE的面积?4×3 = 12 cm2的 BR />六相交,超A,D为AE⊥BC DF⊥BC∵ABCD是等腰梯形AD = EF = 3cm的

∴BE = CF = 4厘米∵AB = CD = 5厘米∴ AE = DF = 3CM∵AE