Question

6) For equation
5x+3y +11=0 and 2x+4y =-10
find D?​

Answer 1

Answer:

5 3

2. 4

= (5×4)-(2×3)

D = 20-6

D = 14

Answer 2

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♧Question♧

• For equation
• 5x+3y +11=0 and 2x+4y =-10
• find D.

♧Answer♧

Let the D = ( x , y )

• ➠5x + 3y + 11 = 0.
• ➠5x + 3y = -11. e.q 1
• ➠2x + 4y = -10. e.q 2

☆Now multiply the equation 1 with 2

• ➠5x + 3y = -11
• ➠2(5x + 3y = -11)
• ➠10x + 6y = -22 e.q 3

☆Now multiply equation 2 with 5

• ➠2x + 4y = -10
• ➠5(2x + 4y = -10)
• ➠10x + 20y = -50. e.q 4

☆Now subtracting e.q 3 and e.q 4

• ➠(10x + 20y = -50) - (10x + 6y = -22)
• ➠-14y = 28
• ➠y = -12/-28
• ➠y = -2

☆Now put the value of y in e.q 1.

• ➠5x + 3y = -11.
• ➠5x + 3(-2) = -11
• ➠5x - 6 = -11
• ➠5x = - 11 + 6
• ➠5x = - 5
• ➠x = -5/5
• ➠x = -1

☆So the value of is D = ( -1 , -2 ).

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