# ncert solutions for class 8 maths chapter 12 exercise 12.4

In this page we have ncert solutions for class 8 maths chapter 12 exercise 12.4 for Factorisation.This exercise has questions about common mistakes/error done while doing factorisation Hope you like them and do not forget to like , social share and comment at the end of the page.

## NCERT solutions for class 8 maths chapter 12 ex 12.4

Question 1
Find and correct the errors in the statement: 4(x - 5) = 4x - 5
LHS =4(x-5) = 4x-20
RHS = (4x-5)
LHS≠ RHS
Correct statement would be
4(x-5) = 4x-20

Question 2
Find and correct the errors in the statement: x(3x + 2) = 3x2 + 2
LHS = x(3x + 2) = 3x2 + 2x
RHS = 3x2 + 2
LHS≠ RHS
Correct statement would be
x(3x + 2) = 3x2 + 2x

Question 3
Find and correct the errors in the statement: 2x + 3y = 5xy
LHS = 2x + 3y
RHS = 5xy
LHS≠ RHS
Correct statement would be
2x + 3y = 2x+3y

Question 4
Find and correct the errors in the statement: x + 2x + 3x = 5x
LHS = x + 2x + 3x= 6x
RHS = 5x
LHS≠ RHS
Correct statement would be
x + 2x + 3x= 6x

Question 5
Find and correct the errors in the statement: 5y + 2y + y - 7y = 0
LHS = 5y + 2y + y - 7y = y
RHS = 0
LHS≠ RHS
Correct statement would be
5y + 2y + y - 7y = y

Question 6
Find and correct the errors in the statement: 3x + 2x = 5x2
LHS = 3x + 2x =5x
RHS = 5x2
LHS≠ RHS
Correct statement would be
3x + 2x =5x

Question 7
Find and correct the errors in the statement: (2x)2 + 4(2x) + 7 = 2x2 + 8x + 7
LHS = (2x)2 + 4(2x) + 7 =4x2 +8x+7
RHS = 2x2 + 8x + 7
LHS≠ RHS
Correct statement would be
(2x)2 + 4(2x) + 7 =4x2 +8x+7

Question 8
Find and correct the errors in the statement: (2x)2 + 5x = 4x + 5x = 9x
LHS = (2x)2 + 5x =4x2+5x
RHS = 4x + 5x =9x
Third = 9x
LHS≠ RHS =third part
Correct statement would be
(2x)2 + 5x = 4x2+5x

Question 9
Find and correct the errors in the statement: (3x + 2)2 = 3x2 + 6x + 4
LHS = (3x + 2)2 =9x2 +12x+4
RHS = 3x2 + 6x + 4
LHS≠ RHS
Correct statement would be
(3x + 2)2 =9x2 +12x+4

Question 10
Find and correct the errors in the statement: (y - 3)2 = y2 - 9
LHS = (y - 3)2 =y2 -6y+9
RHS = y2 - 9
LHS≠ RHS
Correct statement would be
(y - 3)2 =y2 -6y+9

Question 11
Find and correct the errors in the statement: (z + 5)2 = z2 + 25
LHS= (z + 5)2 =z2 +10z+25
RHS = z2 + 25
LHS≠ RHS
Correct statement would be
(z + 5)2 =z2 +10z+25

Question 12
Find and correct the errors in the statement: (2a + 3b) (a - b) = 2a2 - 3b2
LHS= (2a + 3b) (a - b)=2a2 -2ab+3ab-3b2=2a2 +ab-3b2
RHS = 2a2 - 3b2
LHS≠ RHS
Correct statement would be
(2a + 3b) (a - b)=2a2 +ab-3b2

Question 13
Find and correct the errors in the statement: (a + 4) (a + 2) = a2 + 8
LHS= (a + 4) (a + 2) =a2 +2a+4a+8=a2 +6a+8
RHS = a2 + 8
LHS≠ RHS
Correct statement would be
(a + 4) (a + 2) =a2 +6a+8

Question 14
Find and correct the errors in the statement: (a - 4) (a - 2) = a2 - 8
LHS= (a - 4) (a - 2) =a2 -2a-4a+8=a2 -6a+8
RHS = a2 - 8
LHS≠ RHS
Correct statement would be
(a - 4) (a - 2) =a2 -6a+8

Question 15
Find and correct the errors in the statement:  3x2/3x2  =0
LHS= 3x2/3x2  =1
RHS =0
LHS≠ RHS
Correct statement would be
3x2/3x2  =1

Question 16
Find and correct the errors in the statement: (3x2+1)/3x2 =  1+1=2
LHS= (3x2+1)/3x2 =  1 + 1/3x2
RHS =1+1
LHS≠ RHS
Correct statement would be
(3x2+1)/3x2 =  1 + 1/3x2

Question17
Find and correct the errors in the statement: 3x/(3x+2) = 1/2
LHS= 3x/(3x+2)
RHS =1/2
LHS≠ RHS
Correct statement would be
3x/(3x+2) =3x/(3x+2)

Question 18
Find and correct the errors in the statement:
3/(4x+3) =1/4x
LHS= 3/(4x+3)
RHS =1/4x
LHS≠ RHS
Correct statement would be
3/(4x+3) =3/(4x+3)

Question 19
Find and correct the errors in the statement:
(4x+5)/4x =5
LHS= (4x+5)/4x =1 + 5/4x
RHS =5
LHS≠ RHS
Correct statement would be
(4x+5)/4x =1 + 5/4x

Question 20
Find and correct the errors in the statement: (7x+5)/5  =7x
LHS= (7x+5)/5  = 7x/5 +1
RHS =7x
LHS≠ RHS
Correct statement would be
(7x+5)/5  = 7x/5 +1

## Summary

1. NCERT solutions for class 8 maths chapter 12 Exercise 12.1 has been prepared by Expert with utmost care. If you find any mistake.Please do provide feedback on mail. You can download the solutions as PDF in the below Link also
2. This chapter 12 has total 3 Exercise 12.1,12.2,13.3 as per latest syllabus. Exercise 12.4 is the deleted exercise. This is the deleted exercise in the chapter.You can explore previous exercise of this chapter by clicking the link below