(3⁹³+3⁹⁰) :(3¹⁷.3⁷³⁾

^{= ( 3 mũ 93 + 3 mũ 90 ) :  3 mũ  90}

^{=  3 mũ 93}

2⁷⁸ ( 1 + 2+ 4) : [ 2⁷⁵ ( 4 + 2 + 1)]

2^{78 :} 2⁷⁵ = 2³ = 8

x

<=> (3²+1 ).3^3(x-2) =3¹⁷+3¹⁵

^<=> (3²+1 ).3^3(x-2) =3¹⁵.(3²+1)

<=> 3^3(x-2)  = 3¹⁵

<=> 3(x-2) = 15

<=> x-2 = 5

<=> x= 7

thuong cua hai so la 4 tuc la so lon gap 4 lan so be va du 19 tuc la 19dv . ta co so do nhu sau: so be:\----\. minh khong biet go ki tu de ve so do nen minh dien giai bang loi nhe. so be se la 1 phan .so lon se la 4 phan  hieu so phan bang nhau la: 4-1=3(phan).so be la; (133-19):3*1=38.so lon la: 133+38=171

171 dung 10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000%

\(\frac{3}{5}\)+ \(\frac{5}{6}\)=\(\frac{18}{30}\)+ \(\frac{25}{30}\)=\(\frac{43}{30}\)

bài này đề sai và bạn kia làm cũng sai rồi

SEVEN

có 4 cháu

2con rể

2con gái

2 cháu rể

1 bà

tất cả 9 người

xs

Cùng bớt đi 19 đơn vị thì hiệu không thay đổi và bằng 120.

Ta tìm hai số sau khi bớt mỗi số đi 19 đơn vị. Hiệu là 120, tỉ lệ là 2 : 1 (số lớn 2 phần, số bé 1 phần).

=> Hiệu số phần là 2 - 1 = 1 phần

1 phần tương ứng 120 => 1 phần = 120

=> Số bé (sau khi bớt 19) là 120

     Số lớn (sau khi bớt 19) là 2 phần x 120 = 240

Vậy số bé ban đầu là: 120 + 19 = 139

       Số lớn ban đầu là: 240 + 19 = 259