Question

How do you evaluate `(3x + 9h ) ^ { 2}`?

Answer 1

`(3x+9h)^2=color(green)(9x^2+54xh+81h^2)`

Explanation:

In general, we know `(color(red)a+color(blue)b)^2=color(red)a^2+2color(red)acolor(blue)b+color(blue)b^2`

For `(color(red)(3x)+color(blue)(9h))^2`
this becomes
`color(white)("XXX")(color(red)(3x))^2+2(color(red)(3x))(color(blue)(9h))+(color(blue)(9h))^2`

`color(white)("XXX")=9x^2+54xh+81h^2`