2 câu trả lời
19+45+76+54+56+100+70
= (76 + 54) + (19 + 45 + 56) + 100 + 70
= 130 + 120 + 100 + 170
= (130 + 70) + 100 + 120
= 420
`19+45+76+54+56+100+70`
`=64+76+54+56+100+70`
`=250+100+70`
`=350+70`
`=420`
19+45+76+54+56+100+70
= (76 + 54) + (19 + 45 + 56) + 100 + 70
= 130 + 120 + 100 + 170
= (130 + 70) + 100 + 120
= 420
`19+45+76+54+56+100+70`
`=64+76+54+56+100+70`
`=250+100+70`
`=350+70`
`=420`
