Please expand this equation and simplify: (2x + 5)(9x -4)

There are 4 multiplication equations that need to be done:1) (2x) x (9x) = 18x²2) (2x) x (-4) = -8x3) (5) x (9x) = 45x4) (5) x (-4) = -20Write this out as an equation: 18x² - 8x + 45x - 20 This simplified becomes 18x² + 37x - 20