A) \[=4{{x}^{2}}+6x\,-10\]
B) \[=4{{x}^{2}}+6x\,-20\]
C) \[=4{{x}^{2}}+8x\,-20\]
D) \[=5{{x}^{2}}+8x\,-20\]
Correct Answer: A
Solution :
Given, \[\operatorname{A} = 3{{x}^{2}}- 4x + 1, B = 5{{x}^{2}}+ 3x - 8 and C = 4{{x}^{2}}-7x+ 3\] (i) \[\left( A+ B \right)-C=(3{{x}^{2}}-4x+1+5{{x}^{2}}+3x-8)-\left( 4{{x}^{2}}-7x+3 \right)\] On combining the like terms, \[=\,\,(3{{x}^{2}}+5{{x}^{2}}- 4x+ 3x + 1 - 8)- \left( 4{{x}^{2}}-7x + 3 \right)\] \[=\,\,\left( 8{{x}^{2}}-x-7 \right)-\left( 4{{x}^{2}}-7x+3 \right)\] \[=8{{x}^{2}}-x-7-4{{x}^{2}}+7x\,-3=8{{x}^{2}}-4{{x}^{2}}-x+7x\,-7-3\] \[=4{{x}^{2}}+6x\,-10\]
You need to login to perform this action.
You will be redirected in
3 sec
