\(a,142\times12+142\times18=142\times\left(12+18\right)=142\times30=4260\\ b,49\times365-39\times365=365\times\left(49-39\right)=365\times10=3965\\ c,4\times18\times25=\left(4\times25\right)\times18=100\times18=1800\)
a) 142 x 12 + 142 x 18
=142x(12+18)
=142x30
=4260
b) 49 x 365 - 39 x 365
=(49-39)x365
=10x365
=3650
c) 4 x 18 x 25
=4x25x18
=100x18
=1800
a, =142. (12+18)
=142. 30
= 4260
b, = 365. (49-39)
= 365. 10
=3650
c,= 18. (25.4)
= 18. 100
=1800
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\(\text{a) 142 x 12 + 142 x 18}\)
\(=142\times\left(12+18\right)\)
\(=142\times30\)
\(=\text{4260}\)
\(\text{b) 49 x 365 - 39 x 365}\)
\(=\left(49-39\right)\times365\)
\(=10\times365\)
\(=3650\)
\(\text{c) 4 x 18 x 25}\)
\(=\left(4\times25\right)\times18\)
\(=100\times18\)
\(=1800\)
