SA3 marksYear: 2020MediumCBSE Class 10
quadratic-equationssolving
Question
Solve for x: x+41−x+71=3011, x=−4,7.
Solution
1
x+41−x+71=3011⇒(x+4)(x+7)x+7−x−4=3011
+1 mark3
⇒(x−2)(x−1)=0⇒x=2,1
+0.5 marks4
Alternative method: x+41+x+71=3011 leading to 11x2+121x+218=0. D=5049. x=22−121±5049 +1 mark