Question

7/13 . 5/19 + 7/19 . 8/13 + 12/19
Mọi người làm tính nhanh hộ mình nhé!!!!!Mình gấp lắm rồi!

Answer 1

    \(\dfrac{7}{19}\).\(\dfrac{5}{19}\) + \(\dfrac{7}{19}\).\(\dfrac{8}{13}\) + \(\dfrac{12}{19}\)

=   \(\dfrac{7}{19}\).( \(\dfrac{5}{13}+\dfrac{8}{13}\)) + \(\dfrac{12}{19}\)

= \(\dfrac{7}{19}\) . \(\dfrac{13}{13}\) + \(\dfrac{12}{19}\)

= \(\dfrac{7}{19}\) + \(\dfrac{12}{19}\)

= \(\dfrac{19}{19}\)

= 1 

Answer 2

   719197​.519195​ + 719197​.813138​ + 12191912​

=   719197​.( 513+813135​+138​) + 12191912​

= 719197​ . 13131313​ + 12191912​

= 719197​ + 12191912​

= 19191919​

= 1 

Answer 3

= 35/13.19 + 56/13.19 + 12.13/13.19

= 35/13.19 + 56/13.19 + 156/13.19

= 35/a + 56/a + 156/a

a = 13.19

a = 13(20 - 1)

a = 13.20 - 13.1

a = 260 - 13

a = 247

=> 35/a + 56/a + 156/a = 35/247 + 56/247 + 156/247 = 247/247 = 1

Đây nhé bạn :D

Answer 4

cô ơi cô đây là 7/13 . 5/19 mà ko phải 7/19 . 5/19 đâu cô

Answer 5

cô lạc đề rồi cô ơi

Answer 6

=\(\dfrac{1}{19}x\left(\dfrac{35}{13}+\dfrac{56}{13}+12\right)=\dfrac{1}{19}x\left(7+12\right)=1\)

Answer 7

= \(\dfrac{7}{19}\)x(\(\dfrac{5}{13}\)+\(\dfrac{8}{13}\))+\(\dfrac{12}{19}\)

=\(\dfrac{7}{19}\)x\(\dfrac{13}{13}\)+\(\dfrac{12}{19}\)

=\(\dfrac{7}{19}\)+\(\dfrac{12}{19}\)

=\(\dfrac{19}{19}\)=1 nha