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# S.chand books class 8 maths solution chapter 15 Linear Equations exercise 15 A

## EXERCISE 15 A

Solve the following equations:

Question 1

3(x+1) + 4x = 24
Sol :

⇒ 3x+3+4x=24

⇒ 7x=24-3

⇒ 7x=21

Question 2

16-2(3y+5) = 4(y-2)
Sol:

⇒16-6y-10=4y-8

⇒16-10+8=4y+6y

⇒24-10=10y

⇒14=10y

⇒y=1.4

Question 3

3(z+1)+4(z+0.3) = 20z + 0.98
Sol:

⇒3z+3+4z+1.2=20z+0.98

⇒7z+4=20z+0.98

⇒4-0.98=20z-7z

⇒3.02=13z

⇒z=0.23

Question 4

7m-4(m+6) = 7(m-8)+4

Sol :

⇒7m-4m-24=7m-56+4

⇒3m-24=7m-52

⇒52-24=7m-3m

⇒28=4m

⇒m=7

Question 5

Sol :

Take L.C.M of 2 and 3 = 6

⇒x=18

Question 6

Sol :

⇒13(4x+8)=5(91+5x)

⇒52x+104=455+25x

⇒52x-25x=455-104

⇒27x=351

⇒x=13

Question 7

Sol :
L.C.M of 2 and 3 is 6

⇒3(3x+1)=6(3x-7)

⇒9x+3=18x-42

⇒42+3=18x-9x

⇒9x=45

⇒x=5

Question 8

Sol :
L.C.M of 2 and 6 is 6

⇒3(14x+5)=6(2x+4)

⇒42x+15=12x+24

⇒42x-12x=24-15

⇒30x=9

Question 9

Sol :

⇒5(9x-5)=7(6x+2)

⇒45x-25=42x+14

⇒45x-42x=14+25

⇒3x=39

⇒x=13

Question 10

Sol :

⇒2(7-6x)=9x

⇒14-12x=9x

⇒14=9x+12x

⇒14=21x

Question 11

Sol:

⇒(2x-1)(9x-3)=(6x-1)(3x+1)

⇒2x.9x-9x+3=6x.3x-3x-1

⇒18x2-9x+3=18x2-3x-1

⇒18x2-18x2-9x+3x+3-1=0

⇒-6x+2=0

⇒2=6x

Question 12

Sol :

⇒4-11y+3y2=1(2+5y+3y2)

⇒4-11y+3y2=2+5y+3y2

⇒4-2-11y-5y+3y2-3y^2=0

⇒2-6y=0

⇒2=6y

Question 13

Sol :

⇒3(-3x+12)=-4(4x+5)

⇒-9x+36=-16x-20

⇒16x-9x=-20-36

⇒7x=-56

⇒x=-8

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