\(A=5+8+...+302\)

\(=\frac{\left(5+302\right)\left[\left(302-5\right):3+1\right]}{2}\)

\(=\frac{30700}{2}=15350\)

 \(B=7+11+15+...+203\)

\(=\frac{\left(7+203\right)\left[\left(203-7\right):4+1\right]}{2}\)

\(=\frac{10500}{2}=5250\)

\(=\frac{6^{80}}{9^{80}}=\left(\frac{6}{9}\right)^{80}=\left(\frac{2}{3}\right)^{80}\)

36.18+36.82+64.141-64.41

= 36 ( 18 + 82 ) + 64 ( 141 - 41 )

= 36 . 100 + 64 . 100

= 100 ( 36 + 64 )

= 100 . 100 

= 10000

36.18+36.82+64.141-64.41=36.(18+82)+64.(141-41)

                                           =36.100+64.100

                                           =(36+64).100

                                           =100.100

                                           =10000

chúc bạn học tốt

So trang co 1 c/s la:

(9-1):1+1=9(trang)

So trang co 2 c/s la:

(99-10):1+1=90(trang)

So trang co 3 c/s la:

(262-100):1+1=163(trang)

Vay so c/s de danh so trang quyen sach day 262 trang la:

1.9+2.90+3.163=678(c/s)

Dung thi k ung ho minh nha!

Chuc bai nay cua bn duoc diem cao nhe!

3. ( x-6)² = 27

     (x-6)² = 9

      x - 6 = 3

      x = 9

5^x+1 = 125

5^x+1 = 5³

=> x+1 = 3

      x = 2

\(2019^{2019}-1=2019^{2019}-1^{2019}⋮2019-1=2018⋮2018\)

easy S < S.2⁸