Question

tính nhanh

45 x ( 55 + 117 ) + 55 x ( 117 - 45 )

Answer 1

45 x ( 55 + 117 ) + 55 x ( 117 - 45 )

= (45 x 55 - 45 x 55) + (45 + 55) x 117

= 0  + 100 x 117 = 11700

Answer 2

\(45\times\left(55+117\right)+55\times\left(117-45\right)\)

\(=45\times55+45\times117+55\times117-55\times45\)

\(=\left(45\times55-45\times55\right)+45\times117+55\times117\)

\(=45\times117+55\times117\)

\(=117\times\left(45+55\right)\)

\(=117\times100\)

\(=11700\)