( x + 1) + ( x + 2) + ... + ( x + 28 ) = 153
Tìm x, biết:
\(\frac{\left(4^x\right)^2}{2^x}\)=8
b) \(3^{x+2}\)-\(9^{4-x}\)= 0
c)\(3^{x+2}\)+\(3^{x-1}\)-\(3^x\)= 297
d)\(5^{x+3}\)-\(5^{x+2}\)+28 = 153
Ta có : \(\frac{\left(4^x\right)^2}{2^x}=8\)
\(\Rightarrow4^{2x}=8.2^x\)
\(\Rightarrow4^{2x}=2^3.2^x\)
\(\Rightarrow\left(2^2\right)^{2x}=2^{x+3}\)
\(\Rightarrow2^{4x}=2^{x+3}\)
=> 4x = x + 3
=> 3x = 3
=> x = 1
Vậy x = 1.
Bài 1:
a) ( x + 1 ) + 5.( x + 2 ) = 23
b) x + 30%x = 1,3
c) ( x + 1 ) + ( x +2 ) +.....+ ( x + 28 ) = 153
d) 64. x - x . 13 - x = 50
f) abc : x = abcabc ( trên đầu chữ abc và abcabc có dấu gạch trên đầu)
GIÚP MÌNH NHA VÌ MÌNH ĐANG CẦN GẤP!
a) ( x + 1 ) + 5.( x + 2 ) = 23
=>x+1+5x+10=23
=>6x+11=23
=>6x=23-11
=>6x=12
=>x=12:6
=>x=2.
Vậy x=2.
b) x + 30%x = 1,3
=>x+0,3x=1,3
=>x.(1+0,3)=1,3
=>x.1,3=1,3
=>x=1,3:1,3
=>x=1.
Vậy x=1.
c)( x + 1 ) + ( x +2 ) +.....+ ( x + 28 ) = 153
=>28x+406=153(chỗ này ta dùng công thức tính tổng số hạng của dãy số liên tiếp)
=>28x=153-406
=>28x=-253
=>x=253/28.
Vậy x=253/28.
d) 64. x - x . 13 - x = 50
=>x.(64-13-1)=50
=>x.50=50
=>x=50:50
f) abc : x = abcabc
=>x=abc:abcabc
=>x=1/abc.
Vậy x=1/abc.
=>x=1.
Vậy x =1.
a) (x+1)+5.(x+2)=23
x+1+5.x+10=23
6x+1=23-10=13
6x=12
x=2
b) x+30%x=1,3
x.(1+3/10)=1,3
x.1,3=1,3
x=1
c)(x+1)+(x+2)+...+(x+28)=153
x+1+x+2+...+x+28=153
x.[(28-1):1+1]+(1+2+...+28)=153
28.x+[(28+1).28:2]=153
28.x+406=153
28.x=-253
Tiếp theo là j nhỉ? Bí đây.
d)64.x-x.13-x=50
x.(64-13-1)=50
50.x=50
x=1
f) Xin lỗi nhx phần này mk chịu r.
tìm x
[ x * ( x + 1 ) ] : 2 = 153
(\(x\) \(\times\) (\(x\) + 1)): 2 = 153
(\(x\) \(\times\) (\(x\) + 1)) = 153 \(\times\) 2
\(x\) \(\times\) (\(x\) + 1) = 306
\(x\)2 + \(x\) = 306
\(x^2\) + \(x\) - 306 = 0
\(x^2\) - 17\(x\) + 18\(x\) - 306 =0
\(x\) \(\times\) (\(x\) - 17) + 18 \(\times\) (\(x\) - 17) = 0
(\(x\) - 17)\(\times\) ( \(x\) + 18) = 0
\(\left[{}\begin{matrix}x-17=0\\x+18=0\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=17\\x=-18\end{matrix}\right.\)
\(\text{#040911}\)
\(x\cdot\left(x+1\right)\div2=153\)
\(\Rightarrow x\cdot\left(x+1\right)=153\cdot2\)
\(\Rightarrow x\cdot\left(x+1\right)=306\)
\(\Rightarrow x^2+x=306\)
\(\Rightarrow x^2+x-306=0\)
\(\Rightarrow x^2+18x-17x-306=0\)
\(\Rightarrow\left(x^2+18x\right)-\left(17x+306\right)=0\\ \Rightarrow x\left(x+18\right)-17\left(x+18\right)=0\\ \Rightarrow\left(x-17\right)\left(x+18\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x-17=0\\x+18=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=17\\x=-18\end{matrix}\right.\\ \text{Vậy, x }\in\left\{-18;17\right\}.\)
\(x\left(x+1\right):2=153\)
\(x\left(x+1\right)=306\)
\(x^2+x=306\)
\(x=17;x=-18\)
tìm x
[ x * ( x + 1 ) ] : 2 = 153
\(\text{#040911}\)
\(\left[x\cdot\left(x+1\right)\right]\div2=153\\ \Rightarrow x\cdot\left(x+1\right)=153\cdot2\\ \Rightarrow x\cdot\left(x+1\right)=306\\ \Rightarrow x^2+x=306\\ \Rightarrow x^2+x-306=0\\ \Rightarrow x^2+18x-17x-306=0\\ \Rightarrow\left(x^2+18x\right)-\left(17x+306\right)=0\\ \Rightarrow x\left(x+18\right)-17\left(x+18\right)=0\\ \Rightarrow\left(x-17\right)\left(x+18\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x-17=0\\x+18=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=17\\x=-18\end{matrix}\right.\\ \text{Vậy, x }\in\left\{-18;17\right\}.\)
tìm x
a, ( x* ( x + 1) : 2 = 153
\(x\cdot\left(x+1\right):2=153\)
\(\Rightarrow x\left(x+1\right)=153\cdot2\)
\(\Rightarrow x^2+x=306\)
\(\Rightarrow x^2+x-306=0\)
\(\Rightarrow x^2+18x-17x-306=0\)
\(\Rightarrow x\left(x+18\right)-17\left(x+18\right)=0\)
\(\Rightarrow\left(x-17\right)\left(x+18\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=17\\x=-18\end{matrix}\right.\)
tinh bang cach thuan tien nhat.
a, 1357 x 28 + 73 x 1357 - 1357.
b, 121 + 125 + 129 + 133 +137 + 141 + 145 + 149 + 153.
1357 x 28 + 73 x 1357 - 1357 = 1357 x 28 + 72 x 1357 = 1357 x ( 72 + 28 ) = 1357 x 100 = 135700 . tick đ-ú-n-g nhé
a, 1357 x (28 + 73 - 1)
= 1357 x ( 101 - 1)
= 13 57 x 100
= 135700
b, 121+125+129+133+137+141+145+149+153
=(121+149)+(125+145)+(129+141)+(137+133)+153
=170+170+170+170+153
=170x4+153
=680+153
=833
Bài 1 : Tìm x
96-x.(x+1)=42
Bài 2 : Tính Nhanh
a,19.27+47.81+19.20
b,87.23+13.93+70.87
Bài 3: Tính Tổng
a,1+4+7+...+79
b,15+17+19+21+...+151+153+155
c,15+25+35+...+115
d,24+25+28+...+125+126
Bài 1 : Tìm x
96-x.(x+1)=42
x(x+1)=138
2x+x=138
3x=138
x=46
Bài 2 : Tính Nhanh
a,19.27+47.81+19.20
=19.(27+20)+47.81
=19.47+47.81
=47(19+81)
=47.100
=4700
b,87.23+13.93+70.87
=87.(23+70)+13.93
=87.93+13.93
=93.(87+13)
=93.100
=9300
Bài 3: Tính Tổng
a,1+4+7+...+79
=(79+1).27:2
=80.27:2
=2160:2
=1080
b,15+17+19+21+...+151+153+155
=(155+15).71:2
=160.71:2
=11360:2
=5680
c,15+25+35+...+115
=130.11:2
=1430:2
=715
d,24+25+28+...+125+126
=150.103:2
=7725
Tìm x:
a) 31-2(x+3)=21
b) (x-11):7+5=7
c)37+49(x-6)=45
d)153-5(x+4)=28
e) 3x+5x=16
g) 4x+5x+7=34
h) 2(x+2)+(x+2)=6
k) 2(x+2)+3x=19
l) 3(x+1)+2(x+2)=117
m) 5(x+2)+3(x+4)+18=48
GIÚP MÌNH VỚI ,MÌNH ĐANG CẦN GẤP.CẢM ƠN!
a) 31 - 2 ( x + 3 ) = 21
2 ( x + 3 ) = 31 - 21
2 ( x + 3 ) = 10
x + 3 = 10 : 2
x + 3 = 5
x = 5 - 3
x = 2
b) ( x - 11 ) : 7 + 5 = 7
( x - 11 ) : 7 = 7 - 5
( x - 11 ) : 7 = 2
( x - 11 ) = 2 x 7
x - 11 = 14
x = 14 + 11
x = 25
b) ( x - 11 ) : 7 + 5 = 7
( x - 11 ) : 7 = 7 - 5
( x - 11 ) : 7 = 2
( x - 11 ) = 2 x 7
x - 11 = 14
x = 14 + 11
x = 25
Bài 1: Tính nhanh
A, 1968 x 15 + 1968 x 84 + 1968
B, 6412 + 5378 + 3582 + 4628
C, 178 x 101 - 178
D, 153 x 8 + 153 + 153
a: \(1968\cdot15+1968\cdot84+1968\)
\(=1968\left(15+84+1\right)\)
\(=1968\cdot100=196800\)
b: \(6412+5378+3582+4628\)
\(=\left(6412+4628\right)+\left(5378+3582\right)\)
\(=11040+8960=20000\)
c: \(178\cdot101-178\)
\(=178\cdot101-178\cdot1\)
\(=178\left(101-1\right)=178\cdot100=17800\)
d: \(153\cdot8+153+153\)
\(=153\left(8+1+1\right)\)
\(=153\cdot10=1530\)