[tex]\implies {\blue {\boxed {\boxed {\purple {\sf {C) \:x\:=\:3}}}}}}[/tex]
[tex]\large\mathfrak{{\pmb{\underline{\red{Step-by-step\:explanation}}{\red{:}}}}}[/tex]
[tex]18 = 3 + 5x[/tex]
➺[tex] \: 5x = 18 - 3[/tex]
➺[tex] \: 5x = 15[/tex]
➺[tex] \: x = \frac{15}{5} [/tex]
➺[tex] \: x = 3[/tex]
[tex]\sf \bf {\boxed {\mathbb {To\:verify:}}}[/tex]
[tex]18 = 3 + 5x[/tex]
➺[tex] \: 18 = 3 + 5 \times 3[/tex]
➺[tex] \: 18 = 3 + 15[/tex]
➺[tex] \: 18 = 18[/tex]
➺[tex] \: L.H.S.=R. H. S[/tex]
Hence verified.
[tex]\large\mathfrak{{\pmb{\underline{\orange{Mystique35 }}{\orange{❦}}}}}[/tex]
