using identies evaluate the following-- (12.1)sq.-(7.9)sq.?
Answers
Answered by
0
take (12+0.1)^2-(7+0.9)^2
then use (a+b)^2=a^2+b^2+2ab
then use (a+b)^2=a^2+b^2+2ab
Answered by
2
(12.1)^2 - (7.9)^2
(10+2.1)^2 - (10-2.1)^2
10^2 + 2.1^2 +2(10)(2.1) - 10^2 +2.1^2 -2(10)(2.1)
2.1^2+2.1^2
44.1+44.1
88.2
(10+2.1)^2 - (10-2.1)^2
10^2 + 2.1^2 +2(10)(2.1) - 10^2 +2.1^2 -2(10)(2.1)
2.1^2+2.1^2
44.1+44.1
88.2
Similar questions