Tim a , b nguyen biet:a-b=ab
1.tim ab biet:a,b=b,a*3+1,3
2.tim ab biet:â*ab=abb+ab
3.tim abc biet:abc+acb=ccc
tim x nguyen biet:
a 8.(x mu 2 +3).(5-x)
b)(2x + 1)mu 2=25
c) (1-3x)mu3 =64
d)(4-x)mu3 =-27
e) xmu2 -5x =0
b: \(\left(2x+1\right)^2=25\)
=>\(\left[{}\begin{matrix}2x+1=5\\2x+1=-5\end{matrix}\right.\)
=>\(\left[{}\begin{matrix}2x=4\\2x=-6\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-3\end{matrix}\right.\)
c: \(\left(1-3x\right)^3=64\)
=>\(\left(1-3x\right)^3=4^3\)
=>1-3x=4
=>3x=1-4=-3
=>x=-3/3=-1
d: \(\left(4-x\right)^3=-27\)
=>\(\left(4-x\right)^3=\left(-3\right)^3\)
=>4-x=-3
=>x=4+3=7
e: \(x^2-5x=0\)
=>\(x\left(x-5\right)=0\)
=>\(\left[{}\begin{matrix}x=0\\x-5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=5\end{matrix}\right.\)
tim 2 so a va b biet:a-b=0,9va a nhân 6-b=6,4
tim ba so a;b;c biet:a+b-c=-3;a-b+c=11;a-b-c=-1
tim a,b thuoc N* biet:a+b=224,UCLN(a,b)=56
ai nhanh mk tick
tim tong hai so tu nhien lien tiep a va b biet:a<2014,589<b
tim STP a,b biet:a,b*6-a,b=1a,b
ai lam truoc mkinh tick
a,b . 6 - a,b = 1a,b
a,b . 5 = 10 + a,b
a,b . 4 = 10 (cùng bớt a,b)
a,b = 10 : 4
a,b = 2,5
tim a va b biet:a<b
và a+b=42
bcnn {a,b} la 72
tim so tu nhien a,b,c,d nho nhat biet:a/b=15/21;b/c=9/12;c/d=9/11