Simplifying –8.3 + 9.2 – 4.4 + 3.7.
Identify and explain any errors in his work or in his reasoning
Original problem 1. −8.3 + 9.2 + 4.4 + 3.7
Additive inverse 2. −8.3 + 4.4 + 9.2 + 3.7 (error, not additive inverse; +3-3=0)
Commutative property 3. −8.3 + (4.4 + 9.2 + 3.7)
Associative property 4. −8.3 + 17.3
Simplify 5. 9
Answer:
No
Step-by-step explanation:
The way to find the line of best fit by estimate is to have about half the points be above and below the line of best fit. In this case Tariq followed the first few points of the data but his estimate would be very off after 10 on the x axis. This would not accurately predict what the next data point could be.
The fencing line x is the height of a rectangle triangle of base = y, hypothenuse of 9 m, so we use Pythagoras theorem to solve:
hyp^2 = height^2 + base^2
9^2 = x^2 + y^2
x^2 = 81 - y^2
we can see that x is also the height of another rectangle triangle of base = 15 - y, hypothenuse of 12 m, so we use Pythagoras theorem to solve:
hyp^2 = height^2 + base^2
12^2 = x^2 + (15 - y)^2
lets expand:
144 = x^2 + 225 - 30y + y^2
substitute x^2 from the first equation in the last:
144 = 81 - y^2 + 225 - 30y + y^2
144 = 81 + 225 - 30y
30y = -144 + 81 + 225
y = 5.4 m
substitute in the fence equation:
x^2 = 81 - y^2
x^2 = 81 - 5.4^2
x = 7.2 m that is the length of the fence
Answer: B 5 and 5 square root 3
Step-by-step explanation:
The answer would be D 1 x 10-5..
