Question

What is the following product? (x square root 7 - 3 square root 8) (x square root 7 - 3 square root 8)

Answer 1

7 x² - 6 x √56 +72

Explanation:

Let's consider the following equation.

(x√7 - 3√8).(x√7 - 3√8)

This is equal to a squared binomial.

(x√7 - 3√8)²

This is equal to the square of the first term, minus the double of the product of the first by the second plus the square of the second term.

(x√7)² - 2 × x√7 × 3√8 + (3√8)²

7 x² - 6 x × √(7.8) + 9 . (√8)²

7 x² - 6 x √56 +72

Answer 2

7x^2 -6x√56 + 72

Explanation:

(x√7 - 3√8)(x√7 - 3√8) ➡ (x√7 - 3√8)^

x^2 × 7 - 3x√56 - 3x√56 + 9×8 ➡ 7x^2 -6x√56 + 72