Question

Find value of X and Y By substitution method.
$2x - 3y + 8 = 0 \\ x - 4y + 7 = 0$
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Answer 1

Solution:

Given equations:

• 2x - 3y + 8 = 0
• x - 4y + 7 = 0

Rewriting these equations we get:

→ 2x - 3y = -8 and x - 4y = -7

Consider the first equation as Eqn (1) and second equation as Eqn (2).

Considering Eqn. 1, we get:

→ 2x - 3y = -8

→ 2x = -8 + 3y

→ x = ( -8 + 3y ) / 2 ... Eqn (3)

Substituting this value of x in Eqn. 2, we get

→ ( -8 + 3y )/2 - 4y = -7

Taking LCM and solving,

→ ( -8 + 3y - 8y) / 2 = -7

Transposing 2 to the RHS,

→ ( -8 - 5y ) = -14

→ -5y = -14 + 8

→ -5y = -6

→ y = 6/5

Substituting value of 'y' in Eqn 3, we get:

→ x = ( -8 + 3( 6/5 ) ) / 2

→ x = ( -8 + 18/5 ) / 2

→ x = (-40 + 18 ) / 10

→ x = -22/10 = -11/5

Therefore the value of x is -11/5 and value of y is 6/5.

Answer 2

Given:-

→2x-3y+8=0–(1)

→x-4y+7=0–(2)

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To Find:-

→The Value of x&y, Using Substitution method?

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AnsWer:-

★From (1)★

→2x-3y+8=0

→2x-3y=-8

→2x=-8+3y

→x=$\frac{-8+3y}{2}$–(3)

•Use (3) in (2)•

→$\frac{-8+3y}{2}$-4y=-7

→-8+3y-4y=-7×2

→-y=-14+8

→-y=-6

→y=6–(4)

♦Use (4) in (3)♦

→x=$\frac{-8+3×6}{2}$

→x=$\frac{-8+18}{2}$

→x=$\frac{\cancel{10}}{\cancel{2}}$

→x=5–(5)

★From (4)&(5) we know,★

๛x=5

๛y=6

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