Tim x biet (x:2+3)x6+7=25
tim x biet 7+x/12=2/3 b)25-x/18=1/2
Ta có (7+x)/12=2/3
suy ra 3(7+x)=24
suy ra 7+x=8
x=1
Ta có (25-x)/18=1/2
suy ra 2(25-x)=18
suy ra 25-x=9
x=16
Bai 1 : Tim x , biet :
a) (32 - x ) + (-7 +I x I ) - (I x I + 25 ) = 25
32-x-7+I x I - 25 = 25 ( bước này cô mk làm hộ )
b) 1 + { -2 - [ -3 +( -4 + I x I)]} = 1-[2-(-3-4)]
mai mk học rồi , giúp nha, I x I là giá trị tuyệt đối của x !!!
1.a,tim x biet
a,5x+5x+1-50=102
b,10x3x-3x+281
c,tinh a=19x310-311 trên 37x63
tim x thuoc z
1)26-|x+9|=-13
2)|x+7|-13=25
tim x biet
1)123-3.(x+4)=23
2)720:[41-(2x-5)]=23.5
Tìm x thuoc z:
1) \(26-\left|x+9\right|=-13\)
\(\Leftrightarrow\left|x+9\right|=26-\left(-13\right)\)
\(\Leftrightarrow\left|x+9\right|=39\)
\(\Leftrightarrow\left[{}\begin{matrix}x+9=39\\x+9=-39\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=39-9=30\\x=-39-9=-48\end{matrix}\right.\)
Vậy: \(x\in\left\{30;-48\right\}\)
2) \(\left|x+7\right|-13=25\)
\(\Leftrightarrow\left|x+7\right|=25+13=38\)
\(\Leftrightarrow x+7\in\left\{38;-38\right\}\)
\(\Leftrightarrow x\in\left\{31;-45\right\}\)
Vậy:.................
tim x biet
\(1)123-3.\left(x+4\right)=23\)
\(\Leftrightarrow3\left(x+4\right)=123-23\)
\(\Leftrightarrow3\left(x+4\right)=100\)
\(\Leftrightarrow x+4=\frac{100}{3}\)
\(\Leftrightarrow x=\frac{100}{3}-4=\frac{100-12}{3}=\frac{88}{3}\)
Vậy:................
2) Tương tự
Bai 1: Tim ab ; biet ab = b x 9
Bai 2 : Tim ab, biet :
a) ab x 5 = 2ab b) ab = 4ab / 9.
Bai 3 : Tim ab, biet : a 2 = b x 5
Bai 4 : Tim cac so ab biet :
a) a x3 = bx9 b) a x4 = b x6.
Bai 5 :
a) Tim abc, biet a , b , c khac nhau va : a x bc = 91.
b) Tim a , b , c khac nhau biet aa x bc = 1001
tim x,biet
a, 1-[15+11] = x-[25-9]
b,2-x=17-[-5]
c, x-12=[-9]-15
d,9-25=[ 7- x] -[25+7]
a, 1-[15+11] = x-[25-9]
1-16=x-16
-15=-x-16
x=-15+16
x=1
b,2-x=17-[-5]
2-x=17+5
2-x=22
x=2-22
x=-20
c, x-12=[-9]-15
x-12=-24
x=-24+12
x=-12
d,9-25=[ 7- x] -[25+7]
-16=[7-x]-32
[7-x]-32=-16
7-x=-16+32
7-x=16
x=7-16
x=-9
Tim x biet
a) x-2 trên 5 =3/8
b) x-1 trên x+5=6/7
c)x2 trên 6=24/25
a)x-2/5=3/8
(x-2).8=5.3
x-2=5.3:8
x-2=1
=>x=3
b,c )tương tự
tim x biet 1001,1<6x + x6 <1111,1
giup mik vs
tim x biet : 25%x - 7/8 + x = 2/3x
\(25\%x-\frac{7}{8}+x=\frac{2}{3}x\)
<=> \(\frac{1}{4}x-\frac{7}{8}+1x=\frac{2}{3}x\)
<=> \(\frac{1}{4}x+1x-\frac{2}{3}x=\frac{7}{8}\)
<=> \(x\left(\frac{1}{4}+1-\frac{2}{3}\right)=\frac{7}{8}\)
<=> \(x\cdot\frac{7}{12}=\frac{7}{8}\)
<=> \(x=\frac{12}{8}=\frac{3}{2}\)
Bài làm:
Ta có: \(25\%x-\frac{7}{8}+x=\frac{2}{3}x\)
\(\Leftrightarrow\frac{x}{4}+x-\frac{2}{3}x=\frac{7}{8}\)
\(\Leftrightarrow\frac{7}{12}x=\frac{7}{8}\)
\(\Leftrightarrow x=\frac{3}{2}\)