Question

The value of $(10.4{)}^2$ is___

Answer 1

Answer: 108.16

$(10.4{)}^2=(10+0.4{)}^2$
$=(10{)}^2+2\times 10\times 0.4+(0.4{)}^2$
$\text{ Since }(a+b{)}^2=(a{)}^2+2ab+b^2$
$=100+8+0.16=108.16$