Question

${25}^2$ can be expanded and expressed as:

• A. $(20+5{)}^2$
  ${20}^2+5^2$
• B. $(20+5{)}^2$
  ${20}^2+5^2+20\times 5$
• C. $(20+5{)}^2$
  ${20}^2+5^2+2\times 20\times 5$

Answer 1

The correct option is C $(20+5{)}^2$

${20}^2+5^2+2\times 20\times 5$
${25}^2=(20+5{)}^2$
Now, as we know that
$(a+b{)}^2=a^2+b^2+2\times a\times b$
$(20+5{)}^2={20}^2+5^2+2\times 20\times 5$
${25}^2={20}^2+5^2+2\times 20\times 5$