Question

Using identities, evaluate ${3.7}^2.$

• A. 13.67
• B. 13.69
• C. 13.71
• D. 13.73

Answer 1

The correct option is B $13.69$

We have, ${3.7}^2$

$=(3+0.7{)}^2$

$=3^2+(2\times 3\times 0.7)+(0.7{)}^2$ [$\because (a+b{)}^2=a^2+2ab+b^2$]

$=9+4.2+0.49$

$=13.69$

$\therefore {3.7}^2=13.69$