2,5 * 9,6*4 =
1+1*2=
2+2*3=
2+1*1=
5+3*1=
chu y * la nhan
Những câu hỏi liên quan
5*2*3*4+1*3=
1*3*2+1*4*5=
chu y * la nhan
5*2*3*4+1*3
=10*12+3
=120+3
=123
1*3*2+1*4*5
=3*2+4*5
=6+20
=26
k cho mình nha bạn
Đúng 0
Bình luận (0)
bai 1:tim x(chu y dau * la dau nhan)
a)(x+1/4)+(3x-4)+2*(x-3)=1
b)2*(x-3)=3(x+2)-x+1
c)x*(x+3)+x(x-2)=2x*(x-1)
d)(x-1)*3x-2*(x+2)-2x=x(x-1)
a: \(\left(x+\dfrac{1}{4}\right)+\left(3x-4\right)+2\left(x-3\right)=1\)
=>\(x+\dfrac{1}{4}+3x-4+2x-6=1\)
=>\(6x-\dfrac{39}{4}=1\)
=>\(6x=1+\dfrac{39}{4}=\dfrac{43}{4}\)
=>\(x=\dfrac{43}{4}:6=\dfrac{43}{24}\)
b: \(2\left(x-3\right)=3\left(x+2\right)-x+1\)
=>\(2x-6=3x+6-x+1\)
=>2x-6=2x+7
=>-6=7(vô lý)
c: \(x\left(x+3\right)+x\left(x-2\right)=2x\left(x-1\right)\)
=>\(x^2+3x+x^2-2x=2x^2-2x\)
=>3x-2x=-2x
=>3x=0
=>x=0
d: \(\left(x-1\right)\cdot3x-2\left(x+2\right)-2x=x\left(x-1\right)\)
=>\(3x^2-3x-2x-4-2x=x^2-x\)
=>\(3x^2-7x-4-x^2+x=0\)
=>\(2x^2-6x-4=0\)
=>\(x^2-3x-2=0\)
=>\(x=\dfrac{3\pm\sqrt{17}}{2}\)
Đúng 1
Bình luận (0)
1.tim so bi chia trong phep chia cho 12 co thuong la 35 va so du la so le co 2chu so2.hieu cua so lon nhat co 4 chu so khac nhau va so nho nhat co 4 chu sola bao nhieu3.mot hinh chu nhat co chieu dai gap ruoi chieu rong. Neu moi chieu tang them 1m thi duoc hinh chu nhat moi co dien tich tang them 26m2. Tinh chu vi hinh chu nhat4.trung binh cong cua 2 phan so bang 5/12. Phan so thu nhat hon phan so thu hai 1/6. Tim phan so thu nhat5.tim y biet (5/7 - y) nhan 4/5 7/10 + 1/26.hieu 2 so 1/3 so be.To...
Đọc tiếp
1.tim so bi chia trong phep chia cho 12 co thuong la 35 va so du la so le co 2chu so
2.hieu cua so lon nhat co 4 chu so khac nhau va so nho nhat co 4 chu sola bao nhieu
3.mot hinh chu nhat co chieu dai gap ruoi chieu rong. Neu moi chieu tang them 1m thi duoc hinh chu nhat moi co dien tich tang them 26m2. Tinh chu vi hinh chu nhat
4.trung binh cong cua 2 phan so bang 5/12. Phan so thu nhat hon phan so thu hai 1/6. Tim phan so thu nhat
5.tim y biet (5/7 - y) nhan 4/5 =7/10 + 1/2
6.hieu 2 so =1/3 so be.Tong 2 so la 63. Tim so be
1/1+2 + 1/1+2+3 + 1/1+2+3+4+.....+1/ 1+2+3+4+.....+2007
Chu y : la phan so
\(\dfrac{1}{1+2}+\dfrac{1}{1+2+3}+\dfrac{1}{1+2+3+4}+...+\dfrac{1}{1+2+3+...+2007}\)
\(=\dfrac{1}{\dfrac{2\times3}{2}}+\dfrac{1}{\dfrac{3\times4}{2}}+\dfrac{1}{\dfrac{4\times5}{2}}+...+\dfrac{1}{\dfrac{2007\times2008}{2}}\)
\(=\dfrac{2}{2\times3}+\dfrac{2}{3\times4}+\dfrac{2}{4\times5}+...+\dfrac{2}{2007\times2008}\)
\(=2\times(\dfrac{1}{2\times3}+\dfrac{1}{3\times4}+\dfrac{1}{4\times5}+...+\dfrac{1}{2007\times2008})\)
\(=2\left(\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{5}+...+\dfrac{1}{2006}-\dfrac{1}{2007}\right)\)
\(=2\left(\dfrac{1}{2}-\dfrac{1}{2007}\right)\)
\(=1-\dfrac{2}{2007}\)
\(=\dfrac{2005}{2007}\)
Đúng 0
Bình luận (0)
tim 2 so co hieu la 42 biet so thu 1 nhan voi 3 so thu 2 nhan voi 2,5 duoc 2 tich bang nhau
Vì 2,5*3=3*2,5 nên ST1 là 2,5 phần,ST2 là 3 phần.Ta có
ST1:/....../....../.../
ST2:/....../....../....../
Vậy ST1 là:42:(3-2,5)*2,5=210
ST2 là:210+42=252
Đúng 0
Bình luận (0)
1/2 * x + 3/5 *(x -2) bang 3/5
giup minh nhe ! thanks
chu thich : * la dau nhan
2/5: 3/7 nhan 3/7 : 2/5 + 1999
{1- 1/2} nhan { 1 - 1/3} nhan { 1 - 1/4 } nhan { 1 - 1/5}
\(\frac{2}{5}:\frac{3}{7}x\frac{3}{7}:\frac{2}{5}+1999=\)\(\frac{2}{5}x\frac{7}{3}x\frac{3}{7}x\frac{5}{2}+1999=\)\(\left(\frac{2x7x3x5}{5x3x7x2}\right)+1999=\)\(1+1999=2000\)
\(\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{3}\right)x\left(1-\frac{1}{4}\right)x\left(1-\frac{1}{5}\right)\)\(=\left(\frac{2}{2}-\frac{1}{2}\right)\)\(x\left(\frac{3}{3}-\frac{1}{3}\right)\)\(x\left(\frac{4}{4}-\frac{1}{4}\right)\)\(x\left(\frac{5}{5}-\frac{1}{5}\right)\)\(=\frac{1}{2}x\frac{2}{3}x\frac{3}{4}x\frac{4}{5}=\)\(\frac{1x2x3x4}{2x3x4x5}=\frac{1x\left(2x3x4\right)}{\left(2x3x4\right)x5}=\frac{1}{5}\)\(.\)
Đúng 0
Bình luận (0)
2/5:3/7 nhân 3/7:2/5+1999
=2/5 nhân 7/3 nhân 3/7nhân 5/2+1999
=14/15 nhân 15/14+1999
=1+1999
=2000
(1-1/2) nhân (1-1/3) nhân (1-1/4) nhân (1-1/5)
=1/2 nhân 2/3 nhân 3/4 nhân 4/5
=24/120
=1/5
Đúng 0
Bình luận (0)
1/7=8/-x
3x/9=2/6
4/2/5:(-33/10)+x=-1/5/6
(x-2/1/4):(-5/6)=3
-8:(4/1/5x+3/10)=4/4/9
(5,5x-44):(-3/2)=30
(13/10x-15).(-5/14)=3
1/3.(x+5/2)=-2
chu y dau( //)la so tap phan con dau( /) la phan so
\(\frac{4}{\frac{2}{5}}:\left(-\frac{33}{10}\right)+x=-\frac{1}{\frac{5}{6}}\)
\(10:\left(-\frac{33}{10}\right)+x=-\frac{6}{5}\)
\(-\frac{100}{33}+x=-\frac{6}{5}\)
\(x=\frac{302}{165}\)
Đúng 0
Bình luận (0)
35 nhan x + 1/2 : 5/3 - 5/4 = 1/2 x 1/3
3/5 nhan x + 1/2 : 5/3 - 5/4 = 1/2 x 1/3
ban ko tra loi ho minh cau nay a
neu the minh ket ban kieu gi
Đúng 0
Bình luận (0)