PLZZ answer this in a simple method​

One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)

Simplify. −4x^2 (5x^4−3x^2+x−2) −20x^6−12x^4+8x^3−8x^2 −20x^6+12x^4−4x^3+8x^2 −20x^8+12x^4−4x^2+8x −20x^6+12x^4+4x^3−8x^2

3x + 4y = 5 x- 3y = -7 solve by substitution