\(\frac{49^6\times5-7^{11}}{\left(-7\right)^{10}\times5+2\times49^5}\)

\(=\frac{7^{12}\times5-7^{11}}{7^{10}\times5+2\times7^{10}}\)

\(=\frac{7^{11}.\left(5-1\right).7}{7^{10}.\left(5+2\right)}\)

\(=\frac{7^2.4}{6}\)

\(=\frac{55}{6}\)

27 . 49 + 49 . 12 + 10 . 51

= 49 . ( 27 + 12 ) + 10 .51

= 49 . 39 + 10 .51

= 1911 + 510

= 2421

27*49+49*12+10*51

=27*49+49*12+10*(49+2)

=27*49+49*12+10*49+10*2

=49*(27+12+10)+10*2

=49*49+20

=2401+20=2421

27 . 49 + 49 . 12 + 10 . 51

= 49 . ( 27 + 12 ) + 10 .51

= 49 . 39 + 10 .51

= 1911 + 510

= 2421

\(\dfrac{5}{11}:\dfrac{10}{49}-\dfrac{5}{11}.\dfrac{3}{10}+\dfrac{10}{11}.\dfrac{27}{10}\\ =\dfrac{49}{22}-\dfrac{3}{22}+\dfrac{54}{22}\\ =\dfrac{50}{11}\)

` 5/11 : 10/49 - 5/11 . 3/10 + 10/11 . 27/10`

` = 5/11 xx 49/10 - 5/11 . 3/10 + 10/11 . 27/10`

` = 49/22 - 3/22 + 27/11`

` = 49/22 - 3/22 + 54/22`

` = 100/22`

` = 50/11`

{(1+49)*5/20} + {(51+99)*5/20} = 50/4+150/4= 50

{(1+49)*5/20} + {(51+99)*5/20} = 50/4+150/4= 50

9) -48725 - ( 357 - 48725 ) + 300

= - 48725 + ( - 357) + 48725 + 300

= [ ( - 48725 ) + 48725 ] + [ ( - 357) + 300]

= 0 + ( -57)

= - 57

10) 3579 - ( 49 - 5 + 3579 ) + 49

= 3579 + ( -49) + 5 + ( -3579) +49

= [ 3579 + ( -3579) ] + [ ( - 49) + 49] + 5

= 0 + 0 + 5

= 5

9) - 48275 - ( 357 - 48725 ) + 300

= -48275 - 357 + 48725 +  300

= ( - 48725 + 48725 ) + ( -357 + 300)

= -57

10) 3579- ( 49 - 5 + 3579 ) + 49

= 3579 - 49 + 5 - 3579 + 49

= ( 3579 - 3579) + (-49 + 49) + 5

= 0+0+5= 5

a: \(=81\cdot51+49\cdot81=81\cdot100=8100\)

b: \(=371\left(65+25+10\right)=37100\)

a,81*51+49*153-49*72

= 81*51+49*(153-72)

=81*51+49*81

=81*(51+49)

=81*100

=8100