Question

Find the values of a and b for which the following pair of linear equations have infinitely many solutions.
2x + 3y = 7
2ax + ay = 28 - by

Answer 1

ANSWER

A1 = 2 , B1 = 3 ,  C1 = -7

A2 = 2a ,  B2 = a , C2 = -28 + b

FOR INFINITY SOLUTION

A1 / A2 = B1 / B2 = C1 / C2

2/ 2a = 3 / a = -7 / -28 + b

considering

2 / 2a = 3 / a

A = 2/3

considering

3/a = -7 / -28 + b

3/ 2/3 = -7 / -28 + b

3/2 * 1 /3 = -7/ -28 + b

B = 14