a,24.57+43.24
=24.(57+43)
=24.100
=2400
b,12.19+12
=12.(19+1)
=12.20
=12.10.2
=120.2
=240
c,43.27+93.43+57.61+59.57
=43.(27+93)+57.(61+59)
=43.120+57.120
=120.(43+57)
=120.100
=12000
d,64.6+81.4+17.6
=64.6+27.3.2.2+17.6
=64.6+54.6+17.6
=(64+54+17).6
=135.6
=810
a) 24 . 57 + 43 . 24
= 24 . (57 + 43)
= 24 . 100
= 2400
b) 12 . 19 + 12
= 12 . (19 + 1)
= 12 . 20
=240
c) 43 . 27 + 93 . 43 + 57 . 61 +59 . 57
= 43 . ( 27 + 93) + 57 . (61 + 59)
= 43 . 120 + 57 . 120
= 120 . (43 + 57)
= 120 . 100
= 12000
\(a,24\cdot57+43\cdot24\)
\(=24\cdot\left(57+43\right)\)
\(=24\cdot100=2400\)
\(b,12\cdot19+12\)
\(=12\cdot\left(19+1\right)\)
\(=12\cdot20=240\)
\(c,43\cdot27+93\cdot42+57\cdot61+59\cdot57\)
\(=43\cdot\left(27+93\right)+57\cdot\left(61+59\right)\)
\(=43\cdot120+57\cdot120\)
\(= \left(43+57\right)\cdot120\)
\(=100\cdot120=12000\)
\(d,64\cdot6+81\cdot4+17\cdot6\)
\(=\left(64+17\right)\cdot6+81\cdot4\)
\(=81\cdot6+81\cdot4\)
\(=81\cdot\left(6+4\right)\)
\(=81\cdot10=810\)
