Please help me ASAP!!

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

Find the center of the circle that can be circumscribed about efg with e(4,4) f(4,2) g(8,2)

Factor this polynomial completely. x^2-8x+12