Question

solve the following pair of linear equations by substitution method x/7+y/3=5 , x/2-y/9=6

Answer 1

Soln,
x/7 + y/3 = 5
or, (3x + 7y)/21= 5
or, 3x + 7y = 105
or, 3x = 105 - 7y
or, x = (105 - 7y) / 3 ..... (i)
And,
x/2 - y/9 = 6
or, (9x - 2y) / 18 = 6
or, 9x - 2y = 108
or, 9x = 108 + 2y
or, x = (108 + 2y) / 9 ......(ii)
Now,
Eqn(i) = Eqn(ii) [both being values of x]
or, (105 - 7y) / 3 = (108 + 2y) / 9
or, 945 - 63y = 324 + 6y
or, 945 - 324 = 6y + 63y
or, 621 = 69y
or, 621 / 69 = y
Therefore, y = 9
In Eqn(i),
x = (105 - 7 * 9) / 3
= (105 - 63) / 3
= 42 / 3
Therefore, x = 14.

Answer 2

Answer:

hii

Step-by-step explanation:

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