If a - b = 7 and
a2 + b2 = 109,
then the value of ab is:
Answer & explanation
Correct answer: option 2
Given,
a - b = 7
a2 + b2 = 109
( a - b )2 = a2 + b2 - 2ab
49 = 109 - 2ab
ab = 30
If a - b = 7 and
a2 + b2 = 109,
then the value of ab is:
Correct answer: option 2
Given,
a - b = 7
a2 + b2 = 109
( a - b )2 = a2 + b2 - 2ab
49 = 109 - 2ab
ab = 30