Question

$8.7^2=?$

• A. 17.4
• B. 75.69
• C. 17.69
• D. 69.79

Answer 1

Answer:

B. 75.69

$(a+b)^2=a^2+2ab+b^2$

$8.7^2=(8+0.7)^2$

$=8^2+2\times8\times0.7+0.7^2$

$=64+11.2+0.49$

$=75.69$