(82)2 – (18)2By using (a – b)(a + b) = a2 – b2= (82 – 18)(82 + 18)= (64)(100)= 6400

Q15 of 95 Page 94

(82)² – (18)² = ?

(82)² – (18)²

By using (a – b)(a + b) = a² – b²

= (82 – 18)(82 + 18)

= (64)(100)

= 6400

If then

(197 × 203) = ?

If (a + b) = 12 and ab = 14, then (a² + b²) = ?

(82)2 – (18)2 = ?