(i) Given that,
(2a − 1)x + 3y − 5 = 0 ...(1)
3x + (b − 2)y − 3 = 0 ...(2)
So, the given equations are in the form of:
a1x + b1y − c1 = 0 ...(3)
a2x + b2y − c2 = 0 ...(4)
On comparing eq (1) with eq(3) and eq(2) with eq (4), we get
a1 = 2a − 1, b1 = 3, c1 = −5
a2 = 3, b2 = b − 2, c2 = -3(p + q + 1)
For infinitely many solution, we have
a1/a2 = b1/b2 = c1/c2
(2a - 1)/3 = -3/(b - 2) = -5/-3
(2a - 1)/3 = -3/(b - 2) and -3/(b - 2) = -5/-3
2a - 1 = 5 and - 9 = 5(b - 2)
a = 3 and -9 = 5b - 10
a = 3 and b = 1/5
So, a = 3 and b = 1/5.
(ii) Given that,
2x − (2a + 5)y = 5 ...(1)
(2b + 1)x − 9y = 15 ...(2)
So, the given equations are in the form of:
a1x + b1y − c1 = 0 ...(3)
a2x + b2y − c2 = 0 ...(4)
On comparing eq (1) with eq(3) and eq(2) with eq (4), we get
a1 = 2, b1 = - (2a + 5), c1 = −5
a2 = (2b + 1), b2 = −9, c2 = −15
For infinitely many solutions, we have
a1/a2 = b1/b2 = c1/c2
2/(2b + 1) = (-2a + 5)/-9 = -5/-15
2/(2b + 1) = (-2a + 5)/-9 and (-2a + 5)/-9 = -5/-15
6 = 2b + 1 and 2a + 5
3 = b = 5/2 and a = -1
So, a = - 1 and b = 5/2.
(iii) Given that,
(a − 1)x + 3y = 2 ...(1)
6x + (1 − 2b)y = 6 ...(2)
So, the given equations are in the form of:
a1x + b1y − c1 = 0 ...(3)
a2x + b2y − c2 = 0 ...(4)
On comparing eq (1) with eq(3) and eq(2) with eq (4), we get
a1 = a - 1, b1 = 3, c1 = −2
a2 = 6, b2 = 1 − 2b, c2 = −6
For infinitely many solutions, we have
a1/a2 = b1/b2 = c1/c2
(a - 1)/6 = 3/(1 - 2b) = 2/6
(a - 1)/6 = 3/(1 - 2b) and 3/(1 - 2b) = 2/6
a - 1 = 2 and 1 - 2b = 9
a - 1 = 2 and 1 - 2b = 9
a = 3 and b = -4
a = 3 and b = -4
So, a = 3 and b = −4.
(iv) Given that,
3x + 4y − 12 = 0 ...(1)
(a + b)x + 2(a − b)y − (5a − 1) = 0 ...(2)
So, the given equations are in the form of:
a1x + b1y − c1 = 0 ...(3)
a2x + b2y − c2 = 0 ...(4)
On comparing eq (1) with eq(3) and eq(2) with eq (4), we get
a1 = 3, b1 = 4, c1 = −12
a2 = (a + b), b2 = 2(a − b), c2 = – (5a − 1)
For infinitely many solutions, we have
a1/a2 = b1/b2 = c1/c2
3/(a + b) = 4/2(a - b) = 12/(5a - 1)
3/(a + b) = 4/2(a - b) and 4/2(a - b) = 12/(5a - 1)
3(a - b) = 2a + 2b and 2(5a - 1) = 12(a - b)
a = 5b and -2a = -12b + 2
On substituting a = 5b in -2a = -12b + 2, we have
-2(5b) = -12b + 2
−10b = −12b + 2 ⇒ b = 1
Thus a = 5
So, a = 5 and b = 1.
(v) Given that,
2x + 3y − 7 = 0 ...(1)
(a − 1)x + (a + 1)y − (3a − 1) = 0 ...(2)
So, the given equations are in the form of:
a1x + b1y − c1 = 0 ...(3)
a2x + b2y − c2 = 0 ...(4)
On comparing eq (1) with eq(3) and eq(2) with eq (4), we get
a1 = 2, b1 = 3, c1 = −7
a2 = (a − 1), b2 = (a + 1), c2 = - (3a − 1)
For infinitely many solutions, we have
a1/a2 = b1/b2 = c1/c2
2/(a - b) = 3/(a + 1) = -7/(3a - 1)
2/(a - b) = 3/(a + 1) and 3/(a + 1) = -7/(3a - 1)
2(a + 1) = 3(a - 1) and 3(3a - 1) = 7(a + 1)
2a - 3a = -3 - 2 and 9a - 3 = 7a + 7
a = 5 and a = 5
So, a = 5 and b = 1.
(vi) Given that,
2x + 3y − 7 = 0 ...(1)
(a − 1)x + (a + 2)y − 3a = 0 ...(2)
So, the given equations are in the form of:
a1x + b1y − c1 = 0 ...(3)
a2x + b2y − c2 = 0 ...(4)
On comparing eq (1) with eq(3) and eq(2) with eq (4), we get
a1 = 2, b1 = 3, c1 = −7
a2 = (a − 1), b2 = (a + 2), c2 = −3a
For infinitely many solutions, we have
a1/a2 = b1/b2 = c1/c2
2/(a - b) = 3/(a + 2) = -7/-3a
2/(a - b) = 3/(a + 2) and 3/(a + 2) = -7/-3a
2(a + 2) = 3(a - 1) and 3(3a) = 7(a + 2)
2a + 4 = 3a - 3 and 9a = 7a + 14
a = 7 and a = 7
So, a = 7 and b = 1.
(vii) 2x + 3y - 7 = 0, ...(1)
(a - b)x + (a + b)y - 3a - b + 2 = 0 ...(2)
So, the given equations are in the form of:
a1x + b1y − c1 = 0 ...(3)
a2x + b2y − c2 = 0 ...(4)
On comparing eq (1) with eq(3) and eq(2) with eq (4), we get
a1 = 2, b1 = 3, c1 = −7
a2 = (a − b), b2 = (a + b), c2 = −(3a + b - 2)
For infinitely many solutions, we have
a1/a2 = b1/b2 = c1/c2
2/(a - b) = 3/(a + b) = -7/−(3a + b - 2)
2/(a - b) = 3/(a + b) and 3/(a + b) = -7/−(3a + b - 2)
2(a + b) = 3(a - b) and 3(3a + b - 2) = 7(a + b)
2a + 2b = 3a - 3b and 9a + 3b - 6 = 7a + 7b
So, a = 5 and b = 1.
(viii) x + 2y - 1 = 0 ...(1)
(a − b)x + (a + b)y - a - b + 2 = 0 ...(2)
So, the given equations are in the form of:
a1x + b1y − c1 = 0 ...(3)
a2x + b2y − c2 = 0 ...(4)
On comparing eq (1) with eq(3) and eq(2) with eq (4), we get
a1 = 1, b1 = 2, c1 = −1
a2 = (a − b), b2 = (a + b), c2 = −(a + b - 2)
For infinitely many solutions, we have
a1/a2 = b1/b2 = c1/c2
1/(a - b) = 2/(a + b) = -1/−(a + b - 2)
1/(a - b) = 2/(a + b) and 2/(a + b) = -1/−(a + b - 2)
(a + b) = 2(a - b) and 2(a + b - 2) = (a + b)
a + b = 2a - 2b and 2a + 2b - 4 = a + b
So, a = 3 and b = 1.
(ix) 2x + 3y - 7 = 0 ...(1)
2ax + ay - 28 + by = 0 ...(2)
So, the given equations are in the form of:
a1x + b1y − c1 = 0 ...(3)
a2x + b2y − c2 = 0 ...(4)
On comparing eq (1) with eq(3) and eq(2) with eq (4), we get
a1 = 2, b1 = 3, c1 = −7
a2 = 2a, b2 = (a + b), c2 = −28
For infinitely many solutions, we have
a1/a2 = b1/b2 = c1/c2
2/2a = 3/(a + b) = -7/−28
2/2a = 3/(a + b) and 3/(a + b) = 7/28
2(a + b) = 6a and 84 = 7(a + b)
So, a = 4 and b = 8.