Matt is showing his work in simplifying (6.2 − 1.6) − 4.4 + 7.8. identify any error in his work or reasoning.

step 1: (6.2 − 1.6) − 4.4 + 7.8
step 2: 6.2 + (− 1.6 − 4.4) + 7.8 (commutative property)
step 3: 6.2 − 6 + 7.8
step 4: −14 − 6 = 8 (commutative property)
step 5: 14 − 6 = 8

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.

Water flows at a steady rate from a tap. its takes 40 seconds to fill a 4 litre watering can from the tap. the rate at which water flows from the tap is halved. complete: 4 litres into cm3

Estimate the area under the curve f(x) = 16 - x^2 from x = 0 to x = 3 by using three inscribed (under the curve) rectangles. answer to the nearest integer.