1, Tìm x :
93 : ( 60,8 - x ) = 1,86
a) Tìm x
a. X - 14,03 = 15,94 b. X + 15,7 = 60,8
\(a,x-14,03=15,94\) \(b,x+15,7=60,8\)
\(x=15,94+14,03\) \(x=60,8-15,7\)
\(x=29,97\) \(x=45,1\)
a. x-14,03 = 15,94
x = 15,94 + 14,03
x =29,97
b. x + 15,7 = 60,8
x = 60,8 - 15,7
x = 45,1
X x 9,6 + X : 2,5 = 60,8
\(\Leftrightarrow x\cdot10=60.8\)
hay x=6,08
Đặt tính rồi tính:
60,8 x 45
Tính nhanh :
9,6 x 2,5 + 60,8
400 x 0,25
Tìm x :
3 * ( x + 1) + 5 * ( x+ 2 ) = 93
3 * x + 3 + 5 * x + 10 =93
8 * x = 93 - 13
8 * x = 80
x = 80 / 8 =10
Tìm x,biết:
x:0,25+x:0,5+x+x*93=24,6
`x:0,25+x:0,5+x+x xx93=24,6`
`x xx4+x xx2+x+x xx93=24,6`
`x xx(4+2+1+93)=24,6`
`x xx100=24,6`
`x=24,6:100`
`x=0,246`
tìm x
x - ( 97 + 93) = 1968
x- (97 + 93)=1968
x- 190=1968
x=1968+190
x= tự tìm =))
các bạn có biết bài 5x -20=0 và bài [x -3+2]=9-2x
x - 190 = 1968
x = 1968 + 190
x = 2158
nếu sai thì mik xin lỗi
Tính :
1,1 + 2,3 + 3,3 + 4,4 + 5,5 + ..........+ 99,0 + 100,1
Tính bằng cách thuận tiện nhất :
a.20,17 x 60,8 + 20,17 x 39,2
b. 9,36 x 12,76 - 2,5 x 12,76 + 12,76 x 3,14
a, 20,17 x 60,8 + 20,17 x 39,2
=20,17 x ( 60,8+39,2 )
=20,17 x 100
=2017
b, 9,36 x 12,76 - 2,5 x 12,76 +12,76 x 3,14
=12,76 x ( 9,36-2,5+3,14 )
=12,76 x10
=127,6
cho bt A=\(\dfrac{\sqrt{x}+1}{\sqrt{x}-1}+\dfrac{\sqrt{x}-1}{\sqrt{x}+1}\dfrac{3\sqrt{x}+1}{x-1}\)(với x≥0;x≠1)
1)rút gọn bt A
2)tính A khi x=9
3)tìm x để A <1
1) \(A=\dfrac{\left(\sqrt{x}+1\right)^2+\left(\sqrt{x}-1\right)^2-3\sqrt{x}-1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{x+2\sqrt{x}+1+x-2\sqrt{x}+1-3\sqrt{x}-1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{2x-3\sqrt{x}+1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{\left(2x-2\sqrt{x}\right)-\left(\sqrt{x}-1\right)}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{\left(2\sqrt{x}-1\right)\left(\sqrt{x}-1\right)}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{2\sqrt{x}-1}{\sqrt{x}+1}\)
b) \(A=\dfrac{2\sqrt{9}-1}{\sqrt{9}+1}=\dfrac{5}{4}\)
c) \(A=\dfrac{2\sqrt{x}-1}{\sqrt{x}+1}< 1\Rightarrow2\sqrt{x}-1< \sqrt{x}+1\Rightarrow\sqrt{x}< 2\Rightarrow x< 4\)
\(1,A=\dfrac{x+2\sqrt{x}+1+x-2\sqrt{x}+1-3\sqrt{x}-1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\\ A=\dfrac{2x-3\sqrt{x}+1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}=\dfrac{\left(\sqrt{x}-1\right)\left(2\sqrt{x}-1\right)}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}=\dfrac{2\sqrt{x}-1}{\sqrt{x}+1}\\ 2,x=9\Leftrightarrow A=\dfrac{6-1}{3+1}=\dfrac{5}{4}\\ 3,A< 1\Leftrightarrow\dfrac{2\sqrt{x}-1-\sqrt{x}-1}{\sqrt{x}+1}< 0\\ \Leftrightarrow\dfrac{\sqrt{x}-2}{\sqrt{x}+1}< 0\Leftrightarrow\sqrt{x}-2< 0\left(\sqrt{x}+1>0\right)\\ \Leftrightarrow x< 4\Leftrightarrow0\le x< 4\)