B−(−18)+cb-\left(-\dfrac{1}{8}\righ t)+c b−(− 8 1 )+c b, minus, left parenthesis, minus, start fraction, 1, divided by, 8, end fraction, right parenthesis, plus, c where b=2b = 2 b=2 b, equals, 2 and c=−74c = -\dfrac{7}{4} c=− 4 7

the answer would be  

a.

3: 1

step-by-step explanation:

a and c

for infinitely many solutions we require both left and right sides to be equal

distribute and simplify

a

14 - 8x = 20 - 8x - 6 = 14 - 8x ← both sides equal so infinite solutions

b

6x - 54 = 6x - 54 + x = 7x - 54 ← not equal

c

4x + 16 = 4x + 10 + 6 = 4x + 16 ← both sides equal so infinite solutions

d

5x - 40 + 10 = 5x + 10

5x - 30 = 5x + 10 ← not equal