225

225

225

15 x 15 =225

15x15=225

15x15=225

`8-1/15 xx 15/3`

`= 8- 15/45`

`= 8-1/3`

`= 24/3 -1/3`

`= 23/3`

\(8-\dfrac{1}{15}\)x\(\dfrac{15}{3}\)

\(=8-\)\(\dfrac{15}{45}\)

\(=8-\dfrac{1}{3}\)

\(=\dfrac{24}{3}-\dfrac{1}{3}\)

\(=\dfrac{23}{3}\)

chúc bạn học tốt:>

6x6 toi chua biet

Cung lam la 5x5

chịu 2x2 còn chưa biết

= 1.1! + (3 - 1).2! + (4 - 1).3! + ...+ (16 - 1).15!

= 1! + 3.2! - 2! + 4.3! - 3! + ...+16.15! - 15!

= 1! + 3! - 2! + 4! - 3! + ...+16! - 15!

= 1! + (3! + 4! + ...+ 16!) - (2! + 3! + ...+ 15!)

= 1 + 16! - 2! = ....  

Ta có:  1x1!+2x2!+......+15x15!

= 1.1! + (3 - 1).2! + (4 - 1).3! + ...+ (16 - 1).15!

= 1! + 3.2! - 2! + 4.3! - 3! + ...+16.15! - 15!

= 1! + 3! - 2! + 4! - 3! + ...+16! - 15!

= 1! + (3! + 4! + ...+ 16!) - (2! + 3! + ...+ 15!)

= 1 + 16! - 2! 

Vậy ...............

hok tốt

71x45+15x15+9x100+180

=71x45+5x3x15+9x5x20+45x4

=45x(71+5+20+4)

=45x100=4500

71 x 45 + 15 x 15 + 9 x 100 + 180

= 71 x 45 + 5 x 3 x 15 + 9 x 5 x 20 + 45 x 4

= 45 x ( 71 + 5 + 20 + 4 )

= 45 x 100

= 4500

Ta có: 71 x 45 + 15 x 15 + 9 x 100 + 180

= 71 x 45 + 5 x 45 + 45 x 20 + 45 x 4

= 45 x ( 71 + 5 + 20 + 4 )

= 45 x 100

= 4500

\(A=\dfrac{1}{15}\times\dfrac{15}{13}\times\dfrac{13}{9}\times9\)

\(A=\dfrac{1}{15}\times\dfrac{15}{13}\times\dfrac{13}{9}\times\dfrac{9}{1}\)

\(A=\dfrac{1}{1}\)

\(A=1\)

(Sử dụng phương pháp triệt tiêu(rút gọn)

cày ghê quá hữu nghĩa ơi

Cảm ơn bạn, tớ thấy vẫn bình thường ạ.

15 × 15= 225

10 × 10=100

30×10 =300

Me too

15x15=225

10x10=100

30x10=300

kb vs ib vs mk nhek!

15 . 15 = 225

10 . 10 = 100

30 . 10 = 300

=225

=1224

=3021

k cho mk nha bn

225

1224

3021