Question

câu 18 ai biết chỉ em với 

 

Answer 1

\(-48+48\left(-78\right)+48\left(-21\right)\)

\(=48\cdot\left(-1\right)+48\left(-78\right)+48\cdot\left(-21\right)\)

\(=48\left(-1-78-21\right)\)

\(=-100\cdot48=-4800\)

Answer 2

48 + 48 ( − 78 ) + 48 ( − 21 )

= 48 ⋅ ( − 1 ) + 48 ( − 78 ) + 48 ⋅ ( − 21 )

= 48 ( − 1 − 78 − 21 )

= − 100 ⋅ 48 = − 4800