Usuń nawiasy i zredykuj wyrazy podobne. a) 5x + ( 2x- 7) - 9x - (- 3x + 8) + 20 - 8x b) -5x + ( -2y + 4x) - ( 7x - 8y) -x + (2-6y) c) -9z - ( 4-3z) - 8y - (-7z + 8y ) + ( -2y - 7 ) z obliczeniami!!

a) 5x + ( 2x- 7) - 9x - (- 3x + 8) + 20 – 8x = 5x+ 2x-7-9x+3x-8+20-8x = -7x+5 b) -5x + ( -2y + 4x) - ( 7x - 8y)-x + (2-6y) = -5x-2y+4x-7x+8y-x+2-6y = -9x+2 c) -9z - ( 4-3z) - 8y - (-7z + 8y ) + ( -2y - 7 ) = -9z-4+3z-8y+7z-8y-2y-7 = z-18y-11