If a - b = 3 and a^2 + b^2 = 2 the ab = ?
- 11
- -7
- -7/2
- none
Explanation
a - b = 3
a2 + b2 = 2
the formula used: (a-b)2 = a2 +b2 -2ab
Calculation:
a - b = 3
squaring both sides
a2 + b2 - 2ab = 9
2 - 2ab = 9
2 - 9 - 2ab = 0
-7/2 = ab
Related MCQs
- 8x + 5 = 0
- 8(x + 5) = x
- 8x = x + 5
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
- (x+5)(x−4)/(x−2)(x+2)
- x+5/x+2
- x−4/x−2
- x+5/x−2
اس سوال کو وضاحت کے ساتھ پڑھیں
- 20
- 25
- 30
- 35