b) 6² + 4⁷ : 4⁵ - 2 . 5²
= 36 + 4² - 2 . 25
= 36 + 16 - 50
= 52 - 50
= 2
\(6^2+4^7:4^5-2.5^2\)
\(=6^2+4^{7-5}-2.5^2\)
\(=6^2+4^2-2.5^2\)
\(=36+16-2.25\)
\(=36+16-50\)
\(=52-50\)
\(=2\)
62+47:45-2.52
= 36 + 42-2.25
= 36+16-2.25
= 36+16 -50
=52-50
=2