(-5/7):(-5/7)^39+0,5^19.2^20-1^43-|-25/49| Question (-5/7):(-5/7)^39+0,5^19.2^20-1^43-|-25/49| in progress 0 Toán Liliana 1 năm 2021-08-11T22:51:58+00:00 2021-08-11T22:51:58+00:00 1 Answers 12 views 0
Answers ( )
Giải thích các bước giải:
$(\dfrac{-5}{7}):(\dfrac{-5}{7})^{39}+0,5^{19}.2^{20}-1^{43}-|\dfrac{-25}{49}|$
$=(\dfrac{-5}{7})^{1-39}+0,5^{19}.2^{19}.2-1-\dfrac{25}{49}$
$=(\dfrac{-5}{7})^{-38}+(2.0,5)^{19}.2-1-\dfrac{25}{49}$
$=(\dfrac{5}{7})^{-38}+1^{19}.2-1-\dfrac{25}{49}$
$=(\dfrac{7}{5})^{38}+2-1-\dfrac{25}{49}$
$=(\dfrac{7}{5})^{38}+1-\dfrac{25}{49}$
$=(\dfrac{7}{5})^{38}+\dfrac{49-25}{49}$
$=(\dfrac{7}{5})^{38}+\dfrac{24}{49}$