Bài 1:
a: \(=64\cdot12-16\cdot15=528=2^4\cdot3\cdot11\)
b: \(=49\cdot12-120:8=573=3\cdot191\)
c: \(=2500:25+16\cdot30=480+100=580=2^2\cdot5\cdot29\)
d: \(=123-8\cdot9+16\cdot3=99=3^2\cdot11\)
Bài 2:
a: =>7x-15=6
=>7x=21
hay x=3
b: \(\Leftrightarrow x+3=\dfrac{75}{5}=15\)
hay x=12
c: \(125-3\left(x+3\right)=65\)
=>3(x+3)=60
=>x+3=20
hay x=17
d: \(\Leftrightarrow5x=125-75=50\)
hay x=10