Question

using the suitable identities,evaluate the following
b)7¹-3²​

Answer 1

Step-by-step explanation:

Given, 71 ²

i.e. 71 ² =(70+1) ²

We know,

(x+y) ² =x² +y² +2xy.

Then,

71 ²=(70+1)²

=70 ²+(2×70×1)+1²

=4900+140+1

=5040+1

=5041.

Hence, 71²

=5041.

This is an example!!!