90: 20 + 15*(2) - (23 + 42/9)= 90: 20 + 30 - (23 + 4.67)= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 4.5 + 30 - 27.67= 31.5 - 27.67= 3.83 (approximately)
90: 20 + 15*(2) - (23 + 42/9)
= 90: 20 + 30 - (23 + 4.67)
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 4.5 + 30 - 27.67
= 31.5 - 27.67
= 3.83 (approximately)