a x+35=515/5=103
x=103-35=68
b 3(x+1)=96-42=54
x+1=54/3=18
x=18-1=7
a) \(5\left(x+35\right)=515\)
\(\Rightarrow x+35=103\)
\(\Rightarrow x=68\)
b) \(96-3\left(x+1\right)=42\)
\(\Rightarrow3\left(x+1\right)=54\)
\(\Rightarrow x+1=18\)
\(\Rightarrow x=17\)
c) \(5^x.5=5^4\Rightarrow5^x=5^3\Rightarrow x=3\)
d) \(\left(x-1\right)^2=125\)
Mà \(\orbr{\begin{cases}\left(5\sqrt{5}\right)^2=125\\\left(-5\sqrt{5}\right)^2=125\end{cases}\Rightarrow\orbr{\begin{cases}x-1=5\sqrt{5}\\x-1=-5\sqrt{5}\end{cases}\Rightarrow}\orbr{\begin{cases}x=5\sqrt{5}+1\\x=1-5\sqrt{5}\end{cases}}}\)
Mà lớp 6 chưa học căn
=> Kiểm tra lại đề
Bài 2 : Tìm x :
a) 5 . ( x + 35 ) = 515
<=> x + 35 = 515 : 5
<=> x + 35 = 103
<=> x = 103 - 35
<=> x = 68
Vậy x = 68
b) 96 - 3 . ( x + 1 ) = 42
<=> 3 . ( x + 1 ) = 96 - 42
<=> 3 . ( x + 1 ) = 54
<=> x + 1 = 54 : 3
<=> x + 1 = 18
<=> x = 18 - 1
<=> x = 17
Vậy x = 17
c) 5^x . 5 = 5^4
<=> 5^x . 5^1 = 5^4
<=> 5^x = 5^4 : 5^1
<=> 5^x = 5^4-1
<=> 5^x = 5^3
=> x = 3
Vậy x = 3
a,5(x+35)=515
x+35 =515:5
x+35 =103
x =103-35
x =68
b,96-3(x+1)=42
3(x+1)=96-42
3(x+1)=54
x+1 =54:3
x+1 =18
x =17
c,5x.5=54
5x+1=54
=>x+1=4
x =4-1
x =3
Toán lớp 6
MMS_Hồ Khánh Châu 6 giờ trước (09:32)
Báo cáo sai phạm
a) 5(x+35)=515
⇒x+35=103
⇒x=68
b) 96−3(x+1)=42
⇒3(x+1)=54
⇒x+1=18
⇒x=17
c) 5x.5=54⇒5x=53⇒x=3