(a²+ab)÷(a²-b²)
=a(a+b)÷[(a-b)(a+b)]
=a÷(a-b)
=a/(a+b)
.已知a²-4a+9b²+6b+5=0,求1/a-1/b的值
a²-4a+9b²+6b+5=0
a²-4a+4+9b²+6b+1=0
(a-2)²+(3b+1)²=0
(a-2)²=0,(3b+1)²=0
a=2,b=-1/3
1/a-1/b
=1/2-1/(-1/3)
=1/2+3
=7/2
3.已知x²
4.已知x+1/x=3,求x²÷(x四次方+x²+1)的值
x^2÷(x^4+x^2+1)取倒数
(x^4+x^2+1)÷x^2
=x^2+1+1/x^2
=x^2+2+1/x^2-1
=(x+1/x^2)^2-1
=3^2-1
=9-1
=8
再取倒数
x^2÷(x^4+x^2+1)=1/8
(a²+ab)÷(a²-b²)=?2.已知a²-4a+9b²+6b+5=0,求1/a-1/b的值 3.已知x²
(a²+ab)÷(a²-b²)=?2.已知a²-4a+9b²+6b+5=0,求1/a-1/b的值 3.已知x²
4.已知x+1/x=3,求x²÷(x四次方+x²+1)的值
4.已知x+1/x=3,求x²÷(x四次方+x²+1)的值
数学人气:322 ℃时间:2020-04-08 07:24:00
优质解答
我来回答
类似推荐
猜你喜欢
- 1It\'ll be so much better if you are still with
- 2已知数列{an}的前n项和为Sn,且Sn=n²+2n,(1)数列{an}的通项公式(2)数列{bn}中,b1=1,bn=a(bn-1)(n≥2),求数列{bn}的通项公式!
- 3We shall travel by night ____ by day,or we can'tgey there on time.
- 4某跳伞运动员,体重800牛顿,降落伞的质量是20千克,当伞和运动员在空中匀速下降时,所受到的空气阻力是_N.(g取10N/kg)
- 5高手来帮我翻译成英文一下,谢谢啦
- 6甲筐苹果重量是乙筐的60%,如果甲筐放入苹果8千克,则两筐苹果的重量相等.乙筐有苹果多少千克?
- 7若x取整数,则使分式6x+32x−1的值为整数的x值有( ) A.3个 B.4个 C.6个 D.8个
- 85等于25分之几
- 9Excuse me.Could you tell me how I can exchange money?
- 10性染色体上的基因都与性别有关?(即染色体上的每个基因都决定着性别吗?)