Question

9.8 Rahul and Rajesh were asked to subtract 4x - 5 from x² + 3x - 5. Their solutions are given below Rahul: (x² + 3x - 5)-(4x-5)=x² + 3x-5-4x+5=x²-x Rajesh: (x² + 3x - 5) - (4x - 5) = x² + 3x-5-4x-5=x²-x-10 Who solved the problem correctly and what was the mistake made by the other?​

Answer 1

Explanation:

Rahul correctly solved the problem, because it changed the sign in places when there was a "-" in front of the bracket.

( x² + 3x - 5) - (4x - 5) = x² + 3x - 5 - 4x + 5 = x²-x

-(a+b) = -a-b

-(a-b+c-a+c)= -a+b-c+a-c

Answer 2

Rahul's solution is correct, and Rajesh's solution is incorrect due to the repeated subtraction of the constant term -5.

Rahul solved the problem correctly, while Rajesh made a mistake.

Rahul's solution:

(x² + 3x - 5) - (4x - 5) = x² + 3x - 5 - 4x + 5 = x² - x

Rajesh's solution:

(x² + 3x - 5) - (4x - 5) = x² + 3x - 5 - 4x - 5 = x² - x - 10

Rajesh made a mistake by subtracting the constant term -5 twice. The correct solution only subtracts the constant term -5 once.

Therefore, Rahul's solution is correct, and Rajesh's solution is incorrect due to the repeated subtraction of the constant term -5.