college algebra
posted by john on .
Perform the indicated operation(s) and express the result in standard form. Leave answers in terms of square roots (do not use decimals).
(9sqrt3)^2

[9 sqrt(3)]^2
let me change that to i notation (i=sqrt1)
[9 i sqrt3]^2
Using FOIL
81+9isqsrt3 +9isqrt3+i^2*3
81+18i*sqrt3 3
78+18i*sqrt3
remember i^2=1