Determine $a+b$ such that the following system of equations:
$2x-(a-4)y=2b+1 \text{ and }4x-(a-1)y=5b-1$ infinite solutions.
Answer is C
infinitely many solns, so $\frac{a_{1}}{a_{2}}=\frac{b_{1}}{b_{2}}=\frac{c_{1}}{c_{2}}$
$\frac{2}{4}=\frac{-(a-4)}{-(a-1)}=\frac{2b+1}{5b-1}$
On solving, we get a = 7 and b = 3
So, (a+b) = 7 + 3 = 10