Answer:
[tex] y = (x+9)^2[/tex]
Step-by-step explanation:
A equation is given to us and we need to convert it into (ax + b)² form . The given equation is ,
[tex]\sf\longrightarrow y = x^2+ 18x + 81 [/tex]
Here we need to complete the whole square of the terms in RHS . We can write it as ,
[tex]\sf\longrightarrow y = x^2+ 2(9)(x) + 9^2 [/tex]
Notice that the RHS is the form of a² + b² + 2ab = (a + b)² . So that ,
[tex]\sf\longrightarrow \underline{\boxed{\red{\sf y = ( x + 9)^2 }}}[/tex]