Solve the following problem posted Give details on solution

Solve the following problem posted. Give details on solution steps. Give advice on how to solve the kind of problem posted below by a classmate (procedure to follow, useful tips to remember, etc. Problem

Perform the indicated operations and write the result in standard form. (-7--2)²

Solution

(-7--2)²

We have to calculate square of the given expression

(a-b)^2=a^2+b^2-2ab

(-7--2)²       = (-7)^2    + (-2)^2   -2(-7)(-2)

(-2)^2 = -2

=49 + (-2) +14(-2)

=47+14(-2)

-1 =i

=47 +14(2)i

Thank you