Question

solve the following equations by substitution method
1) 2x-7y=3,
2) 4x+y=21
​

Answer 1

On multiplying equation one by 2 we get:

4x-14y=6 ...iii

now from ii and iii we get :

15y=15

=>y=1

putting y=1 in i we get :

2x-7=3

=>x=5

hope it helped you !!

Answer 2

ॐ $\red{R}$$\orange{a}$$\green{d}$$\blue{h}$$\purple{e}$     $\red{R}$$\orange{a}$$\green{d}$$\blue{h}$$\purple{e}$ ॐ

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⎟⎟ ✪✪ ＱＵＥＳＴＩＯＮ ✪✪ ⎟⎟

Solve the following equations by substation method :-

• 2x - 7y = 3
• 4x + y = 21

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⎟⎟ ✰✰ ＡＮＳＷＥＲ ✰✰ ⎟⎟

The given two linear equations are

2x - 7y = 3 ---------- ( 1 )

4x + y = 21 ---------- ( 2 )

From the equation ( 2 ) we get y = 21 - 4x now we substitute this 'y' value in equation ( 1 ).

We get 2x - 7 (21 - 4x) = 3

☛ 2x - 147 + 28x = 3

☛ 30x = 147 + 3 = 150

Then x = 150/30 = 5

∴ x = 5

Now put x = 5 in equation ( 2 ) we get

4 ( 5 ) + y = 21

☛ 20 + y = 21

☛ y = 21 - 20 = 1

So x = 5 and

y = 1 are the solution of the system.

∴ $\huge\red{x=5}$ and $\huge\red{y=1}$

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