Question

evaluate 71 square using identity​

Answer 1

Step-by-step explanation:

$(71)^2$

$(70 + 1)^2$

$\small\boxed{(a+b)^2=a^2+2ab+b^2}$

$(70)^2 + 2(70) + 1$

$(4900 + 140 + 1)$

$5041$

Answer 2

$71 {}^{2} = (7 + 1) {}^{2} \\ (7) {}^{2} + 2(7)(1) + (1) {}^{2} \: \\ 49 + 14 + 1 \\ = 64$

Using the identity:

$(a + b) {}^{2} \\ a {}^{2} + 2ab + b {}^{2}$