Answer:
b = 6
Explanation:
solve the second equation for 'y':
-3x + 1/2y = -3
add 3x to each side to get:
1/2y = 3x - 3
multiply all terms by 2 to eliminate the denominator to get:
y = 6x - 6
now compare '6x-6' with '6x-b'
you want both expressions to be equal because then there are an infinite number of solutions:
b = 6