Bài 7:
3 . 24 - 2 . 24
= (3 - 2) . 24
= 1 . 24
= 24.
633 - { [(105 + 3) : 3] - 3}
= 633 - { [108 : 3] - 3}
= 633 - {36 - 3}
= 633 - 33
= 600.
Bài 9:
4x - 3 - 3 . 42 = 42
4x - 3 - 3 . 16 = 16
4x - 3 - 48 = 16
4x - 3 = 16 + 48
4x - 3 = 64
\(\Rightarrow\) 4x - 3 = 43
\(\Rightarrow\) x - 3 = 3
x = 3 + 3
x = 6.
\(3.2^4-2.2^4\)
\(=2^4.\left(3-2\right)\)
\(=2^4.1\)
\(=2^4=16\)
.
\(633-\left\{\left[\left(105+3\right):3\right]-3\right\}\)
\(=633-\left\{\left[108:3\right]-3\right\}\)
\(=633-\left\{36-3\right\}\)
\(=633-33\)
\(=600\)
.
\(4^{x-3}-3.4^2=4^2\)
\(4^{x-3}-4^2=3.4^2\)
\(4^{x-3}-4^2=48\)
\(4^{x-3}=48+4^2\)
\(4^{x-3}=64\)
Ta có: \(4^3=64\)
\(\Rightarrow4^{x-3}=4^3\)
\(\Rightarrow4^x:4^3=4^3\)
\(\Rightarrow4^x=4^3:4^3\)
\(4^x=4^0\)
\(\Rightarrow x=0\)
Vậy \(x=0\)
. Ko hiểu gì hỏi mình nha <3