Question

91-5.(5+x)=61

[195-(3x-27)].39=4212

Answer 1

\(91-5.\left(5+x\right)=61\\ \Rightarrow5.\left(5+x\right)=91-61=30\\ \Rightarrow5+x=\dfrac{30}{5}=6\\ \Rightarrow x=6-5=1\)

 

\(\left[195-\left(3x-27\right)\right].39=4212\\ \Rightarrow195-3x+27=\dfrac{4212}{39}=108\\ \Rightarrow222-3x=108\\ \Rightarrow3x=222-108=114\\ \Rightarrow x=\dfrac{114}{3}=38\)

Answer 2

91-5.(5+x)=61

<=>91-25-5x=61

<=>66-5x=61

<=-5x=-5

<=>x=1

 

Answer 3

\(91-5.\left(5+x\right)=61\)

\(5.\left(5+x\right)=91-61\)

\(5.\left(5+x\right)=30\)

\(5+x=30\div5\)

\(5+x=6\)

\(x=6-5\)

\(x=1\)

\(\left[195-\left(3x-27\right)\right].39=4212\)

\(\left[195-\left(3x-27\right)\right]=4212\div39\)

\(195-\left(3x-27\right)=108\)

\(3x-27=195-108\)

\(3x-27=87\)

\(3x=87+27\)

\(3x=114\)

\(x=114\div3\)

\(x=38\)