Question

Calculate the value of the expression using suitable identity $(12\times 6{)}^2$

• A. 5286
• B. 5182
• C. 5184
• D. 5288

Answer 1

The correct option is C

5184

The given expression is

$(12\times 6{)}^2$

$={\left[\right(9+3)\times (9-3\left)\right]}^2$

$={[9^2-3^2]}^2\left[\right(a+b\left)\right(a-b)=a^2-b^2]$

$=(81-9{)}^2$

$=(72{)}^2$

$=(70+2{)}^2$

$=(70{)}^2+2^2+2\times 70\times 2$

$=4900+4+280$

$=5184$