1.-25x^2+5x+22.(x^2-x)^2+10(x^2-x)-243.(y^2-3)^2+4y(y^2-3)+4

纯朴的海南人2022-10-04 11:39:542条回答

1.-25x^2+5x+2
2.(x^2-x)^2+10(x^2-x)-24
3.(y^2-3)^2+4y(y^2-3)+4y^2

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187常客共回答了22个问题 | 采纳率95.5%: 1.
(-5x+2)(5x+1)
2.
(x^2-x-2)(x^2-x+12)
=(x-2)(x+1)(x^2-x+12)
3.
(y^2+2y-3)^2
=[(y-1)(y+3)]^2; 1年前

(（25x^2+200）/(x^2+8))^0.5-((25x^2+20)/30)^0.5=3 amy_jarvis1年前1: shenyu25 共回答了16个问题 | 采纳率81.3%

(（25x^2+200）/(x^2+8))^0.5-((25x^2+20)/30)^0.5=3
(25((x^2+8)/(x^2+8)))^0.5-((25x^2+20)/30)^0.5=3
5-3=((25x^2+20)/30)^0.5
(25x^2+20)/30=4
25x^2+20=120
25x^2=100
x^2=4
x=±2

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-16+25x^2 4a^2-9b^2 0书女1年前1: 白晴天空共回答了20个问题 | 采纳率90%

要分解因式吧?
如果是,则
-16+25x^2
＝25x²-16
=(5x+4)(5x-4)

4a^2-9b^2
=(2a+3b)(2a-3b)

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Let f(x)=25x^2+kx+2,where k is real. Let f(x)=25x^2+kx+2,where k is real. (a) If f(x)=0 has equal roots,find the value(s) of k,leaving your answer(s) in simplest surd form.(3marks) (b) If a is the smaller positive root of the quadratic equation f(x)=0,and one root is half of the other,express,in term of a, (i) the larger root, (ii) the product of the roots. Hence find the roots of the equation and the value of k.(5marks) huangwusheng1年前2: ryanhccc 共回答了16个问题 | 采纳率93.8%

(a) f(x)=25x^2+kx+2=0 has equal roots
delta=k^2-4*25*2=0 k=±10√2
(b) one root is half of the other
hence the larger root is double of the smaller root a
(i) 2a
(ii) 2a^2
a*2a=2/25
a is positive
a=1/5 2a=2/5
1/5+2/5=-k/25
k=-15
the two roots are 1/5 and 2/5
k is -15

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