Question

Please help
Square roots ​

Answer 1

1) 39²
Firstly split it

(30+9)²

(30+9)(30+9)

30×30+30×9+9×30+9×9

900+270+270+81

=>1521



2) 42²

(40+2)²

(40+2)(40+2)

40×40+40×2+2×40+2×2

1600+80+80+4

=>1764

HOPE IT HELPS U.