tim x
a) 2/15-x=3/10 b)(10-4x)+120/23=17
tìm x : a. (10-4x )+120:8 b. 2/15-x=3/10
1. tính (tính nhanh nếu đc)
a) 49-37 +10
b)57.49 +57. 51 -120
c)1250-11.[ 37 (2 . 32 -15)2
2. tìm x
a) 2.x + 17 = 33
b) 4 . ( x -23 ) = 120
a. 49 - 37 + 10 = 12 + 10 = 22
b. 57 . 49 + 57 . 51 - 120 = 57 . ( 49 + 51 ) -120 = 57 . 100 -120 = 5700 - 120 = 5580
c. 1250 - 11 . [ 37 . (2.32 -15)2 ] =1250 - 11 .[ 37. 32 ] = 1250 - 11 . 333 = 1250 - 3663 = -2413
2x + 17 = 3 3
2x + 17 = 27
2x = 27 - 17
2x = 10
x = 10 : 2
x = 5
4 . (x - 23 ) = 12
x - 23 = 12 : 4
x - 23 = 3
x = 23 - 3
x = 20
a)49-37+10
=49-(37+10)
=49-47
=2
b)57.49 +57. 51 -120
=57.(120+57).(51-49)
=57.(177.2)
=57.354
=20178
c)1250-11.[ 37 (2 . 32 -15)2
=1250-11.[37.(2.9-15)2
=1250-11.(37.32)
=1250-11.(37.9)
=1509.333
=502497.
bài 7
4x3 + 12 = 120
b, ( x - 4 )2 = 64
c, ( x + 1 )3 - 2 = 52
d, 136 - ( x + 5)2 = 100
e, 4x = 16
f, 7x. 3 - 147 = 0
g, 2x+3 - 15 = 17
h, 52x-4. 4 = 102
i, (32 - 4x)(7 - x) = 0
k, ( 8 - x)(10 - 2x) = 0
m, 3x + 3x+1 = 108
n, 5x+2 + 5x+1 = 750
a: \(4x^3+12=120\)
=>\(4x^3=108\)
=>\(x^3=27=3^3\)
=>x=3
b: \(\left(x-4\right)^2=64\)
=>\(\left[{}\begin{matrix}x-4=8\\x-4=-8\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=12\\x=-4\end{matrix}\right.\)
c: (x+1)^3-2=5^2
=>\(\left(x+1\right)^3=25+2=27\)
=>x+1=3
=>x=2
d: 136-(x+5)^2=100
=>(x+5)^2=36
=>\(\left[{}\begin{matrix}x+5=6\\x+5=-6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=1\\x=-11\end{matrix}\right.\)
e: \(4^x=16\)
=>\(4^x=4^2\)
=>x=2
f: \(7^x\cdot3-147=0\)
=>\(3\cdot7^x=147\)
=>\(7^x=49\)
=>x=2
g: \(2^{x+3}-15=17\)
=>\(2^{x+3}=32\)
=>x+3=5
=>x=2
h: \(5^{2x-4}\cdot4=10^2\)
=>\(5^{2x-4}=\dfrac{100}{4}=25\)
=>2x-4=2
=>2x=6
=>x=3
i: (32-4x)(7-x)=0
=>(4x-32)(x-7)=0
=>4(x-8)*(x-7)=0
=>(x-8)(x-7)=0
=>\(\left[{}\begin{matrix}x-8=0\\x-7=0\end{matrix}\right.\)
=>\(\left[{}\begin{matrix}x=8\\x=7\end{matrix}\right.\)
k: (8-x)(10-2x)=0
=>(x-8)(x-5)=0
=>\(\left[{}\begin{matrix}x-8=0\\x-5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=8\\x=5\end{matrix}\right.\)
m: \(3^x+3^{x+1}=108\)
=>\(3^x+3^x\cdot3=108\)
=>\(4\cdot3^x=108\)
=>\(3^x=27\)
=>x=3
n: \(5^{x+2}+5^{x+1}=750\)
=>\(5^x\cdot25+5^x\cdot5=750\)
=>\(5^x\cdot30=750\)
=>\(5^x=25\)
=>x=2
tìm x: (10-4x) +120:2^3=17
(10-4x)+120:23=17
(10-4x)+120:8=17
(10-4x)+15=17
10-4x=17-15
10-4x=2
4x=10-2
4x=8
x=8:4
x=2
a ) - 7 -15 + 30
b )10 x 23 - 10 x (-17)c )21 x 3 -7 x[(-32) + 18]d )-20 - [ 10 x (4 mũ 3 - 54) x 5 mũ 2 + 2 mũ 4]a: =30-22=8
b: =10*(23+17)=10*40=400
c: =21*3-7*(-14)
=63+98=161
d: =-20-[10*10*5^2+16]
=-20-100*25-16
=-36-2500
=-2536
Tìm số nguyên x, biết: a) (-15).x = 10.(- 4) - 5; b) (- 3).x - 4 = 2. (- 7) + 4 c) 7.x + l = -13; a) (- 8).x + 17 = - 23;
Tìm x, biết:
a) 72.5–(2x+1)=630:972.5–(2x+1)=630:9
b) (10–4x)+120:23=17
a) 72.5–(2x+1)=630:972.5–(2x+1)=630:9
⇒245–2x–1=70⇒245–2x–1=70
⇒−2x=−22+70⇒−2x=−22+70
⇒−2x=−174⇒−2x=−174
⇒x=87⇒x=87
b)(10−4x)+120:23=17
10−4x+15=17
10−4x=17−15
10−4x=2
4x=10−2
4x=8
x=8:4
x=2
Tim x:
3^2x-4 -x^0 = 8
65- 4^x+2 = 2014^0
120+2. ( 3x + 17) = 214
5^2x-3 - 2.5^2 = 5^2 = 5^2.3
30- [4(x-2)+15] =3
740:(x+10)= 10^2 - 2.13
[(6x-39):7].4= 12
*
\(3^2x-4-x^0=8\)
9x-4-1=8
9x-5=8
9x=13
=>x=\(\frac{13}{9}\)
trả lời nhanh giúp tôi
a, 3(x-6)-11=22
b, 4x-10-10=20
c,5(x+2)+8=23
d,720:(x-17)=12
e,(x-28):12=8
f,26+8x=6x+46
\(a,3\left(x-6\right)-11=22\)
\(\Rightarrow3\left(x-6\right)=22+11=33\)
\(\Rightarrow x-6=33:3=11\)
\(\Rightarrow x=11+6=17\)
\(b,4x-10-10=20\)
\(\Rightarrow4x=20+10+10=40\)
\(\Rightarrow x=40:4=10\)
\(c,5\left(x+2\right)+8=23\)
\(\Rightarrow5\left(x+2\right)=23-8=15\)
\(\Rightarrow x+2=15:5=3\)
\(\Rightarrow x=3-2=1\)