八年级上册数学计算题30道数学八年级上册
(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
  √(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