Question

CÍU E!

Tìm x:

3^2 . (x+4) - 5^2 = 5.22

Answer 1

\(3^2\cdot\left(x+4\right)-5^2=5\cdot22\)

\(\Rightarrow9\cdot\left(x+4\right)-25=110\)

\(\Rightarrow9\cdot\left(x+4\right)=110+25\)

\(\Rightarrow9\cdot\left(x+4\right)=135\)

\(\Rightarrow x+4=\dfrac{135}{9}\)

\(\Rightarrow x+4=15\)

\(\Rightarrow x=15-4\)

\(\Rightarrow x=11\)

Answer 2

`#3107`

\(3^2\cdot\left(x+4\right)-5^2=5\cdot22\\ \Rightarrow3^2\left(x+4\right)=5\cdot22+5^2\\ \Rightarrow9\left(x+4\right)=110+25\\ \Rightarrow9\left(x+4\right)=135\\ \Rightarrow x+4=135\div9\\ \Rightarrow x+4=15\\ \Rightarrow x=15-4\\ \Rightarrow x=11\)

Vậy, `x = 11.`