Question

Bài 4 : Tính nhanh 

a) 52² + 52 . 48

b) 39² - 39 . 29 

c) 99 . 5³  + 125

Answer 1

\(a,\\ 52^2+52.48=52.52+52.48=52.\left(52+48\right)=52.100=5200\\ b,\\ 39^2-39.29=39.39-39.29=39.\left(39-29\right)=39.10=390\\ c,\\ 99.5^3+125=99.125+125=125.\left(99+1\right)=125.100=12500\)

Answer 2

a) 52² + 52 . 48 = 2704 + 2496 = 5200

b) 39² - 39 . 29 = 1521 - 1131 = 390

c) 99 . 5³ + 125 = 99 . 125 + 125 = 12375 + 125 = 12400