Answer :

i. 6x = 72

Dividing both side by 6, we get

x = 12

ii. 9x + 2 = 20

⇒ 9x + 2 – 2 = 20 – 2

⇒ 9x = 18

Dividing both side by 9, we get

⇒ x = 2

iii. 4x – 2x + 3 = 9 – 4x

Simplifying, we get

2x + 3 = 9 – 4x

⇒ 2x + 4x = 9 – 3

⇒ 6x = 6

Dividing both side by 6, we get

⇒ x = 1

iv.

Taking LCM, we get

Cross Multiplying, we get

⇒ -6x = 4(21 – 2x)

⇒ -6x = 82 – 8x

⇒ 8x – 6x = 82

⇒ 2x = 82

Dividing both side by 2

⇒ x = 41

v. 2x – 5{7 – (x – 6) + 3x} – 28 = 39

⇒ 2x – 5(7 – x + 6 + 3x) – 28 = 39

⇒ 2x – 5(13 + 2x) – 28 = 39

⇒ 2x – 65 – 10x – 28 = 39

⇒ 2x – 10x = 39 + 28 + 65

⇒ -8x = 132

Dividing both side by -8, we get

vi.

Taking LCM,

⇒

Cross-Multiplying we get,

⇒ 5(7x + 1) = 12(x + 79)

⇒ 35x + 5 = 12x + 948

⇒ 35x – 12x = 948 – 5

⇒ 23x = 943

Dividing both side by 23, we get

⇒ x = 41

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Let’s factorise :

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andLet’s form a whole square of the expressions given below using the above identities-

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andLet’s find out the square of the expressions given below using the above identities –

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Let’s fill up the table below :

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Let’s fill up the table below:

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Let’s write the area of the rectangular region whose the length is 8x+3y cm. and breadth is 8x – 3y cm.

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