Answer:-25+-12
Step-by-step explanation:so I made x value as 5 so I multiplied -5x5 and it's -25 then I multiplied -4x-7 and that's -12 so the equivalent expression for my way is -25+-12
T = # of text messages
$91.50 = 0.45t + $50
Subtract 50 from both sides
$41.50 = 0.45t
divide by 0.45
92.2 = # of text messages David had
12/x + 7 =13/x, where x is not 0;
<=> 12 + 7x = 13 <=> 7x = 1 <=> x = 1/7;
Answer:
To hit the ground, it will take the watch:
Step-by-step explanation:
Making use of the provided equation:
- <u>h (t) = - 16t ^ 2 + initial height
</u>
Which can be modified specifically for this case:
- <u>h (t) = - 16t ^ 2 + 6400 feet.
</u>
Time must be replaced a certain number of times until the value is zero, this can be done one by one, but since it would be too many iterations I will show you some examples and what you could deduce in each case.
<em>With t = 1 second:
</em>
- h (1) = - 16 (1) ^ 2 + 6400 feet = 6384 feet (only the watch has dropped 16 feet)
<em>With t = 7 seconds:
</em>
- h (7) = - 16 (7) ^ 2 + 6400 feet = 5616 feet (has fallen 784 feet)
<em>With h = 15 seconds:
</em>
- h (15) = - 16 (15) ^ 2 + 6400 ft = 2800 feet (3600 ft has fallen, it is not long)
<em>With h = 21 seconds:
</em>
- h (21) = - 16 (21) ^ 2 + 6400 feet = -656 feet (When obtaining a negative number, it is understood that the time was too long, therefore a shorter time must be taken)
<em>With h = 20 seconds:
</em>
- <u>h (20) = - 16 (20) ^ 2 + 6400 feet = 0 feet
</u>
<u>Since with 20 seconds the exact value of zero is obtained, this time is the exact time it would take the watch to fall to the ground</u>, since when this time is reached the height (h) will be zero, that is, at ground level .
