Iwill mark brainiest is my answe correct? postive 23?

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10

Find the perimeter of the triangle with vertices  d(3, 4),  e(8, 7), and  f(5, 9). do not round before calculating the perimeter. after calculating the perimeter, round your answer to the nearest tenth.  

Mario is constructing a frame for 10 in. by 8 in. photo. he wants the frame to be the same with all the way around in the same area of the frame and photo to be 120 square inches what is the dimension of the frame?