Question

1. Tính nhanh

a, (315+372)×3+(372+315)×7/26×13+74×14

Answer 1

\(\dfrac{\left(315+372\right).3+\left(372+315\right).7}{26.13+74.14}\)

\(=\dfrac{\left(315+372\right)\left(3+7\right)}{2.13.13+74.2.7}\)

\(=\dfrac{687.10}{2\left(169+518\right)}\)

\(=\dfrac{6870}{2.687}=\dfrac{6870}{1374}=5\)

Answer 2

a, [ (315+372) .3 +(372+315).7] /26.13 +74.14

=[ (315+372) .(3+7) ] /26 .13 + 74 .13 +74

= [(315+372).10 ] / (26+74).13 +74

= 687 .10 / 100.13 +74

= 6870 /1374

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Answer 3

\(\dfrac{\left(315+372\right).3+\left(372+315\right).7}{26.13+74.14}\)

\(=\dfrac{687.\left(3+7\right)}{26.13+74.13+74}\)

\(=\dfrac{687.10}{13\left(74+26\right)+74}\)

\(=\dfrac{6870}{1374}=5\)