My teacher suck at show me how to do stuff

Anyone know? is appreciated! will mark brainliest if correct!

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

Given the following linear function sketch the graph of the function and find the domain and range. ƒ(x) = -5x + 4