ohe09nz81r的部落格

標題:

Factorization

發問:

• 手機mon一時用到一時用唔到
• exponent question
• 判別式 ax^2+bx+c=0

• 手機mon一時用到一時用唔到
• exponent question
• 判別式 ax^2+bx+c=0

 

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100(1-x)^2 + 60(x-1) + 9 = ? 5(2x-3)^2 - (3-2x) = ? (a+b)^2 - 3(ab+b^2) = ? 麻煩了... 更新: y99shto.. 第一條 10*10(1-x)^2 - 2*3*10(1-x) + 3*3 點解係變左做 (10(1-x) - 3)^2 ? 唔係好明..

最佳解答:

100(1-x)^2 + 60(x-1) + 9 = 100(1-x)^2 - 60(1- x) + 9 = 10*10(1-x)^2 - 2*3*10(1-x) + 3*3 = (10(1-x) - 3)^2 5(2x-3)^2 - (3-2x) = 5(2x-3)^2 + (2x-3) = (2x-3)(5(2x-3)+1) = (2x-3)(10x-14) = 2(2x-3)(5x-7) (a+b)^2 - 3(ab+b^2) =(a+b)(a+b) - 3(b)(a+b) =(a+b)(a+b - 3b) =(a+b)(a-2b) 2006-11-03 18:27:30 補充： For 1st one..100(1-x)^2 + 60(x-1) + 9= 100(1-x)^2 - 60(1- x) + 9= 10*10(1-x)^2 - 2*3*10(1-x) + 3*3= (10(1-x) - 3)^2= (7-10x)^2= (10x-7)^2

其他解答:

100(1-x)^2 + 60(x-1) + 9 =100(x-1)^2 + 60(x-1) + 9 =(10(x-1)+3)^2 =(10x-7)^2 5(2x-3)^2 - (3-2x) =5(3-2x)^2 - (3-2x) =[3-2x][5(3-2x)-1] =(3-2x)(15-10x-1) =(3-2x)(14-10x) =2(3-2x)(7-5x) 2006-11-03 22:54:08 補充： (a b)^2 - 3(ab b^2)=a^2 2ab b^2-3ab-3b^2=a^2-ab-2b^2|||||1)100-200x+100x^2+60x-60+9=0 100x^2-140x+49=0 x=7/10 2)5(4x^2-12x+9)-3+2x=0 20x^2-58x-42=0 x=7/2 or -3/5 3)a^2+2ab+b^2-3ab-b^2=0 (a-2b)(a+b)=0