A) 232
B) 400
C) 128
D) Cannot be determined
Correct Answer: A
Solution :
Given \[x+y=20\] \[\Rightarrow \] \[{{(x+y)}^{2}}={{(20)}^{2}}\] \[\Rightarrow \] \[{{x}^{2}}+{{y}^{2}}+2xy=400\] \[\Rightarrow \] \[{{x}^{2}}+{{y}^{2}}=400-2\times 84\] \[(\because \,\,xy=84)\] \[=400-168=232\]
You need to login to perform this action.
You will be redirected in
3 sec
