Can you please explain this one^

Sundar used linear combination to solve the system of equations shown. he did so by multiplying the first equation by 5 and the second equation by another number to eliminate the y-terms. what number did sundar multiply the second equation by? 2x+9y=41 3x+5y=36

Acircle has a radius of 12.6cm what is the exact length of an arc formed by a central angle measuring 120

What is the solution to the system of equations? y=1.5-3 y=-x