Question

Đã trả lời bởi chuyên gia

Answer 1

a.

$13.28 + 72.13 + 37 + 37.99 = (13.28 + 72.13) + (37 + 37.99) = 13 . (28 + 72) + 37 . (1 + 99) = 13.100 + 37.100 = 100 . (13 + 37) = 100.50 = 5000$

b.

$18.15 + 35 + 15.32 + 35.49 = (18.15 + 15.32) + (35 + 35.49) = 15 . (18 + 32) + 35 . (1 + 49) = 15.50 + 35.50 = 50 . (15 + 35) = 50.50 = 2500$

c.

$2.19.6 + 3.37.4 + 44.12 = 12.19 + 12.37 + 44.12 = 12 . (19 + 37 + 44) = 12.100 = 1200$

d.

$32.27 + 47.73 + 27.15 = (32.27 + 27.15) + 47.73 = 27 . (32 + 15) + 47.73 = 27.47 + 47.73 = 47 . (27 + 73) = 47.100 = 4700$

e.

$A = 1 + 2 + 3 + 4 + . . . + 50 A = (1 + 50) + (2 + 49) + . . . + (25 + 26) (c ó 50 : 2 = 25 c ặ p) A = 51 + 51 + . . . + 51 A = 51.25 A = 1275$

f.

$B = 2 + 4 + 6 + 8 + . . . + 100$

số số hạng $= \frac{100 - 2}{2} + 1 = 50$ (số)

tổng B $= \frac{(100 + 2) . 50}{2} = 2550$

g.

$47.29 - 13.29 - 24.29 = 29 . (47 - 13 - 24) = 29.10 = 290$

h.

$26.7 + 13.26 - 17.9 - 17.11 = 26 . (7 + 13) - 17 . (9 + 11) = 26.20 - 17.20 = 20 . (26 - 17) = 20.9 = 180$

i.

$18.15 + 35 + 15.32 + 35.49 = (18.15 + 15.32) + (35 + 35.49) = 15 . (18 + 32) + 35 . (1 + 49) = 15.50 + 35.50 = 50 . (15 + 35) = 50.50 = 2500$ 0

k.

$18.15 + 35 + 15.32 + 35.49 = (18.15 + 15.32) + (35 + 35.49) = 15 . (18 + 32) + 35 . (1 + 49) = 15.50 + 35.50 = 50 . (15 + 35) = 50.50 = 2500$ 1

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Answer 2

a.