A) 12
B) 13
C) 14
D) \[-\]5
Correct Answer: D
Solution :
(d): \[{{\left( a-b \right)}^{2}}={{\left( a+b \right)}^{2}}-4ab\] \[=49-48=1\Rightarrow a-b=1\] \[a+b=7\] \[a-b=1\Rightarrow a=4,b=3\] \[{{a}^{2}}-ab-{{b}^{2}}\] \[=16-12-9=-5.\]You need to login to perform this action.
You will be redirected in
3 sec