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Find the values of a and b so that the following

system of linear equations have infinitely solutions:
(1) (2a - 15x + 3y - 5 = 0, 3x + (6 - 1)y - 2 = 0
plz answer step by step​

User Mch
by
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1 Answer

4 votes

Answer:

a = 15/2, b = 2/5

Explanation:

For a system of two linear equations to have infinitely many solutions, the equations must be equivalent to one another.

Assuming a and b to be constants, and since b is absent from equations, there must be a typo where b was mistaken for a 6.

Modified equations:

2a - 15x + 3y - 5 = 0 ...................(1)

3x + (b - 1)y - 2 = 0 .....................(2)

rearrange equations to standard form:

-15x + 3y + 2a-5 = 0 .................(1a)

3x + (b-1)y -2 = 0 ........................(2)

To equalize the coefficient of x, multiply (2) by -5

-15x - 5(b-1) y +10 = 0 ................(2a)

Subtract (2a) from (1a)

3y + 5(b-1)y + 2a-5 -10 = 0 ..............(3)

For the two equations (1a) and (2a) to be identical, coeffients of y and constant term of (3) must equal zero.

3+5(b-1) = 0 .................(4)

3+5b-5 = 0

5b = 2

b = 2/5

2a-5-10 = 0 .....................(5)

a = 15/2

User AllanLRH
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