Question

-93² + 4 × 5 - 20²

Explanation:

Step1: Calculate inside the brackets (PEMDAS: exponents first)

First, calculate \(3^2 = 9\), \(4\times5 = 20\). Then substitute into the bracket: \(9 + 20 - 20\).

Step2: Simplify the bracket

Simplify \(9 + 20 - 20\): \(9+(20 - 20)=9 + 0 = 9\).

Step3: Square the result inside the brackets

Now, square the result from the bracket: \(9^2 = 81\).

Step4: Multiply by -9

Multiply the result by -9: \(-9\times81=-729\).

Answer:

\(-729\)