求初二数学60道计算题、30道实数运算题、30道解方程组(带解)

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第1个回答  2019-05-06
(1)99²-2.99²

(2)80×3.5²+160×3.5×1.5+80×1.5²

(3)181²-61²÷301²-181²
(4)5x-5y+5z

(5)-5a²+25a-5a

(6)2a(b+c)-3(b+c)

(7)(ab+a)+(b+1)
(8)-4m³+16m³-28m

(9)16x-25x³y²

(10)36m²a-9m²a²-36m²
√32-3√1/2+√2
√12+√27/√3-√1/3×√12
√50+√30/√8-4
(√6-2√15)×√3-6√1/2
√2/3-4√216+43√1/6
√8+√30-√2
√40-5√1/10+√10
√2+√8/√2
√2/9+√50+√32
(1-√3)(√3+2)
(√8+3√6)÷√2-√3×√0.7
(-3+√6)(-3-√6)-(√3-1/√3)²
³√0.125-√3
1/16+³√(1-7/8)²
√2/3-√216+42√1/6
解方程√3
X-1=√2
X
求X
{√5
X-3√
Y=1}
{√3
X-√5
Y=2}
注:X全部不在根号内
√(1/2x)^2+10/9x^2
=√[1/(4x^2)+10/(9x^2)]
=√49/36x^2
若x>0,=7/(6x)
若x<0,=-7/(6x)
√a^4mb^2n+1
=√(a^2mb^n)^2+1
=a^2mb^n+1
√(4a^5+8a^4)(a^2+3a+2)
=√[4a^4(a+2)][(a+2)(a+1)]
=√[4a^4(a+2)^2(a+1)]
=2a^2(a+2)√(a+1)
.
3√(1/6)-4√(50)+30√(2/3)
答案3√(1/6)-4√(50)+30√(2/3)
=
3×√6/6-4×5√2+30×√6/3
=√6/2-20√2+10√6
2.
(1-根号2)/2乘以(1+根号2)/2
题是这样的二分之一减根号2乘以二分之一加根号2
答案:(1-根号2)/2乘以(1+根号2)/2
=(1-√2)*(1-√2)/4
=(1-2)/4
=-1/4
1.3√(1/6)-4√(50)+30√(2/3)
答案3√(1/6)-4√(50)+30√(2/3)
=
3×√6/6-4×5√2+30×√6/3
=√6/2-20√2+10√6
2.
(1-根号2)/2乘以(1+根号2)/2
题是这样的二分之一减根号2乘以二分之一加根号2
答案:(1-根号2)/2乘以(1+根号2)/2
=(1-√2)*(1-√2)/4
=(1-2)/4
=-1/4
3.√(1/2x)^2+10/9x^2
√[(1/2x)^2+10/9x^2]
=√(x^2/4+10x^2/9)
=√(9x^2/36+40x^2/36)
=√(49x^2/36)
=7x/6;
4.√a^4mb^2n+1(a、b为正数)
[√(a^4mb^2n)]+1(a、b为正数)
=a^2mb^n+1;
5.√(4a^5+8a^4)(a^2+3a+2)(a>=0)
√[(4a^5+8a^4)(a^2+3a+2)](a>=0)
=√[4a^4(a+2)(a+2)(a+1)]
=√[(2a^2)^2(a+2)^2(a+1)]
=2a^2(a+2)√(a+1).
太多了呀,只能这样了,我还有事
您好!
①5√8-2√32+√50
=5*3√2-2*4√2+5√2
=√2(15-8+5)
=12√2
②√6-√3/2-√2/3
=√6-√6/2-√6/3
=√6/6
③(√45+√27)-(√4/3+√125)
=(3√5+3√3)-(2√3/3+5√5)
=-2√5+7√5/3
④(√4a-√50b)-2(√b/2+√9a)
=(2√a-5√2b)-2(√2b/2+3√a)
=-4√a-6√2b
⑤√4x*(√3x/2-√x/6)
=2√x(√6x/2-√6x/6)
=2√x*(√6x/3)
=2/3*x*√6
⑥(x√y-y√x)÷√xy
=x√y÷√xy-y√x÷√xy
=√x-√y
⑦(3√7+2√3)(2√3-3√7)
=(2√3)^2-(3√7)^2
=12-63
=-51
⑧(√32-3√3)(4√2+√27)
=(4√2-3√3)(4√2+3√3)
=(4√2)^2-(3√3)^2
=32-27
=5
⑨(3√6-√4)²
=(3√6)^2-2*3√6*√4+(√4)^2
=54-12√6+4
=58-12√6
⑩(1+√2-√3)(1-√2+√3)
=[1+(√2-√3)][1-(√2-√3)]
=1-(√2-√3)^2
=1-(2+3+2√6)
=-4-2√6
1.
=5√5
-
1/25√5
-
4/5√5
=√5*(5-1/25-4/5)
=24/5√5
2.=√144+576
=√720
=12√5
3.)√(8/13)^2-(2/13)^2
=
√(8/13+2/13)(8/13-2/13)
=(2/13)√15
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