Question

use the identity and find the square of 189 (a-b)2=a2-2ab+b2​

Answer 1

${189}^{2} \\ = {(190 - 1)}^{2} \\ = {(190)}^{2} - 2(190)(1)+ {(1)}^{2} \\ = 36100 - 380 + 1 \\ = 36101 - 380 \\ = 35721$