a)
(x – 45).27 = 0
x – 45 = 0
x = 0 + 45=45
b)
(34-x) = 42 : 21
34-x = 2
x = 34 - 2 = 32
c)
(2+3)x=1505
5x=1505
x=1505:5 =301.
\((x - 45).27 = 0\)
\((x - 45) = 0:27\)
\(x - 45 = 0\)
\(x = 0+45=45\)
\(------------------\)
\(21.(34 - x) = 42\)
\((34 - x) = 42:21\)
\(34 - x =2\)
\(x=34-2=32\)
\(-------------\)
\(2.x+3.x = 1505\)
\((2+3).x = 1505\)
\(5.x = 1505\)
\(x = 1505:5\)
\(x=301\)
\(--------------\)
\((x - 1).(x-8) = 0\)
\(=>\left[{}\begin{matrix}x-1=0\\x-8=0\end{matrix}\right.=>\left[{}\begin{matrix}x=1\\x=8\end{matrix}\right.\)
\(\text{a},x-45=0:27\\ x-45=0\\ x=45\\ b,34-x=42:21\\ 34-x=2\\ x=32\\ c,x\left(2+3\right)=1505\\ 5x=1505\\ x=301\\ d,\left(x-1\right)=0ho\text{a}cx-8=0\\ x=1;x=8\)
\(\left(x-45\right).27=0\)
\(x-45=0:27\)
\(x-45=0\)
\(x=45+0\)
\(x=45\)
___________________________________
\(21.\left(34-x\right)=42\)
\(34-x=42:21\)
\(34-x=2\)
\(x=34-2\)
\(x=32\)
_________________________
\(2.x+3.x=1505\)
\(x\left(2+3\right)=1505\)
\(x.5=1505\)
\(x=1505:5\)
\(x=301\)
________________________
\(\left(x-1\right).\left(x-8\right)=0\)
TH1: TH2:
\(x-1=0\) \(x-8=0\)
\(x=0+1\) \(x=0+8\)
\(x=1\) \(x=8\)
Vậy \(x=1\) hoặc \(x=8\)
a) (x - 45).27 = 0
x-45=0:27
x-45=0
x=0+45
x=45
b) 21.(34 - x) = 42
34-x=42 : 21
34-x=2
x=34-2
x=32
c)2.x+3.x = 1505
x(2+3)=1505
x.5=1505
x=1505 : 5
x=301
d) (x - 1).(x-8) = 0
\(\rightarrow\left\{{}\begin{matrix}x-1=0\rightarrow x=0+1\rightarrow x=1\\x-8=0\rightarrow x=0+8\rightarrow x=8\end{matrix}\right.\)
