Chọn B

b

a) \(74\frac{19}{35}.\frac{7}{90}+15\frac{16}{35}.\frac{7}{90}+2\frac{14}{90}\)

= \(\left(74\frac{19}{35}+15\frac{16}{35}\right).\frac{7}{90}+2\frac{14}{90}\)

=  90 . 7/90 + 194/90

= 630/90 + 194/90

= 824/90 = 412/45

b) (-2/5 + 3/7) - (4/9 + 12/20 - 13/35) + 7/35

= -2/5 + 3/7 - 4/9 -  3/5 + 13/35 + 7/35

= (-2/5 - 3/5) + 3/7 - 4/9 + (13/35 + 7/35)

= -1 + 3/7 - 4/9 + 4/7

= -1 + (3/7 + 4/7) - 4/9

= -1 + 1 - 4/9 = -4/9

98 x 35 =3430

35 x 90 =3150

98 x 35 = 3430

35 x 90 = 3150

a)X - 15 =90 - 35

x-15=55

x=55+15

x=70

b)X*23 =46 - 0

x*23=46

x=46:23

x=2

c)X +46 = 10

x=10-46

x=-36

a, X= 90 - 35 +15 = 40

B,X=46/23=2

C, X=10-46= - 36

Câu trả lời là:

90 - 35 = 55

Đ/S 55

k nha 

90-35=55

90-35=55

k mk nha mk nhanh nhất

90 and 35 is effective :

90 - 35 = 55

Answer : 55

Ta có:

\(74\frac{19}{35}.\frac{7}{90}+15\frac{16}{35}:\frac{90}{7}\)

\(=74\frac{19}{35}.\frac{7}{90}+15\frac{16}{35}.\frac{7}{90}\)

\(=\frac{7}{90}.\left(74\frac{19}{35}+15\frac{16}{35}\right)\)

\(=\frac{7}{90}.90\)

\(=7\)

\(74\frac{19}{35}.\frac{7}{90}+15\frac{16}{35}.\frac{7}{90}\)

\(\frac{7}{90}.\left(74\frac{19}{35}+15\frac{16}{35}\right)\)

\(\frac{7}{90}.90\)

\(7\)

35+20+55+90=200

35 + 20 + 55 + 90 

= ( 35 + 55 ) + ( 20 + 90 )

= 100 + 110

= 210