Answer:
38
Step-by-step explanation:
Answer:
see explanation
Step-by-step explanation:
The figure shown has one pair of parallel sides and is a trapezium
The area (A) of a trapezium is calculated using
A =
h(a + b)
where h is the height and a, b the length of the parallel sides
here h = 2w, a = w + 3 and b = 4w - 2, hence
A =
× 2w(w + 3 + 4w - 2)
= w(5w + 1) = 5w² + w
Since if he gets the driveway done in 20 minutes he gets 1/20th of the driveway done in 1 minute (if x=20 then x/20=1 by dividing both sides by 20) and if his brother gets 1/12th of the driveway done in one minute, then if t represents the time it takes to shovel the driveway, t/20+t/12=1 driveway shoveled as 1/20+1/12=amount they can do in 1 minute, so t/20+t/12 is how much they can do in t minutes. Multiplying both sides by 20*12=240, we get 12t+20t=32t=240. Dividing both sides by 32, we get 240/32=7.5 minutes to shovel the driveway.
The true statement about Sam’s conjecture is that the conjecture is not correct
<h3>How to determine if Sam’s conjecture is correct or not?</h3>
Sam’s conjecture is given as:
For x ≤ - 2
It is true that x^5 + 7 > x^3.
The inequality x ≤ - 2 means that the highest value of x is -2
Assume the value of x is -2, then we have:
(-2)^5 + 7 > (-2)^3
Evaluate the exponents
-32 + 7 > -8
Evaluate the sum
-25 > -8
The above inequality is false because -8 is greater than -25 i.e. -8 > -25 or -25 < -8
Hence, the true statement about Sam’s conjecture is that the conjecture is not correct
Read more about conjectures at
brainly.com/question/20409479
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