Please help with these questions from math

Simplify.7x + 3y - 2 + 6x + 1 + y squared 2 you! ; )

Which shows the pre image of triangle xyz

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