Answer:
B 5 seconds
Step-by-step explanation:
h = 240 + 32t – 16t^2
When is this equation 0
0 = 240 + 32t – 16t^2
Factor out 16
0 = -16(-15-2t+t^2)
= -16(t^2-2t-15)
What 2 numbers multiply to -15 and add to -2
-5*3 = -15
-5+3 =-2
0 = -16(t-5) (t+3)
Using the zero product property
t-5=0 t+3=0
t=5 t=-3
Since time cannot be negative
t=5 seconds
The answer would be the second option B) because we can cross out A) and D) since those are multiplication, and it's not C) because that's commutative property, not associative.
The complex number -7i into trigonometric form is 7 (cos (90) + sin (90) i) and 3 + 3i in trigonometric form is 4.2426 (cos (45) + sin (45) i)
<h3>What is a complex number?</h3>
It is defined as the number which can be written as x+iy where x is the real number or real part of the complex number and y is the imaginary part of the complex number and i is the iota which is nothing but a square root of -1.
We have a complex number shown in the picture:
-7i(3 + 3i)
= -7i
In trigonometric form:
z = 7 (cos (90) + sin (90) i)
= 3 + 3i
z = 4.2426 (cos (45) + sin (45) i)




=21-21i
After converting into the exponential form:

From part (b) and part (c) both results are the same.
Thus, the complex number -7i into trigonometric form is 7 (cos (90) + sin (90) i) and 3 + 3i in trigonometric form is 4.2426 (cos (45) + sin (45) i)
Learn more about the complex number here:
brainly.com/question/10251853
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Answer:
$280
Step-by-step explanation:
Step one
Given data
A mechanic makes $350 /week
20% of his income is deducted for taxes
Required
the mechanic's take-home pay for the week
Step two:
let us find 20% of $350
=20/100*350
= 0.2*350
=$70
Therefore the take-home pay is
= 350-70
= $280