Question

Answer 1

\(a,\Rightarrow7\left(x-5\right)=49\Rightarrow x-5=7\Rightarrow x=12\\ b,\Rightarrow64-11x=4\cdot5^4:5^3=4\cdot5=20\\ \Rightarrow11x=44\Rightarrow x=4\\ c,\Rightarrow x+6=4^2=16\Rightarrow x=10\\ d,\Rightarrow9\left(15-2x\right)=20+25=45\\ \Rightarrow15-2x=5\\ \Rightarrow2x=10\Rightarrow x=5\)

Answer 2

Bài 8: 

c: =>x+6=16

hay x=10