B1:Tính
a,3.52-16:22
b,22.17-23.14
c,15.141+59.10
d,17.85+15.17-120
e,100-[75-(7-2)]2
g,(23.94+93.45):(92.10-92)
B2:Tìm x
a,420+65.4=(x+175):3+30
b,96-3.(x+1)=42
c,(x-47)-115=0
d,(x-36):18=12
e,2x=16
B3:Tìm x
a,60-3.(x-2)=51
b,4x-20=25:22
c,8.6+288:(x-3)2=50
mk đang càn rất gấp
Bài 3:
a: Ta có: 60-3(x-2)=51
\(\Leftrightarrow x-2=3\)
hay x=5
b: Ta có: \(4x-20=25:2^2\)
\(\Leftrightarrow4x=\dfrac{25}{4}+20=\dfrac{105}{4}\)
hay \(x=\dfrac{105}{16}\)
c: Ta có: \(8\cdot6+288:\left(x-3\right)^2=50\)
\(\Leftrightarrow288:\left(x-3\right)^2=50-48=2\)
\(\Leftrightarrow\left(x-3\right)^2=144\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=12\\x-3=-12\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=15\\x=-9\end{matrix}\right.\)