Question

Which of the following is the correct expansion of (3x-y)2

Answer 1

$\bold{[ \ Answer \ ]}$

$\boxed{\bold{9x^{2} \ - \ 6xy \ + y^{2} }}$

$\bold{[ \ Explanation \ ]}$

• $\bold{Find \ Expansion: \ (3x \ - \ y^{2} )}$

$\bold{----------------------}$

• $\bold{[Apply \ Perfect \ Square \ Formula\ (\left(a-b\right)^2=a^2-2ab+b^2)] \ a \ = \ 3x, \ b \ = \ y}$

$\bold{\left(3x\right)^2-2\cdot \:3xy+y^2}$

• $\bold{[Simplify \ \left(3x\right)^2-2\cdot \:3xy+y^2] \ 9x^2-6xy+y^2}$

= $\bold{9x^2-6xy+y^2}$

$\boxed{\bold{[] \ Eclipsed \ []}}$