:)
I know how to do :):) I am very awesome:):)
1)
\(\sqrt{75360} - \sqrt{0.7536}\\ =\sqrt{7.536 \times 100^2} - \sqrt{75.36\times \left(\dfrac{1}{10}\right)^2}\\ =100\sqrt{7.536} - \dfrac{1}{10}\sqrt{75.36}\\ = 100 \times 2.754 - \dfrac{1}{10}\times 8.681\\ = 275.4 - 0.8681\\ =274.5319\)
2)
90% of the questions = 45 questions.
Let x be the number of questions he got correct.
(45-x) be the number of questions he got wrong.
\(5x + (-2)(45-x) + 0(50 - 45) = 176\\ 5x - 90 + 2x = 176\\ 7x = 266\\ \color{red}\boxed{\color{black}{x=38\\ 45-x = 7}}\)
He got 38 questions correct, and 7 questions wrong.