Answer:
You just gotta multiply then divide it
Step-by-step explanation:
Answer:
The height of the objects are the same after 2 seconds.
Step-by-step explanation:
In order to calculate at which time both objects have the same height we need to find the value of t that makes both equations equal. Therefore:
![-t^2 + 3t = -t + 4\\t^2 - 3t - t + 4 = 0\\t^2 - 4t + 4 = 0\\t_{1,2} = \frac{-(-4) \pm \sqrt{(-4)^2 - 4*1*4}}{2*1} = \frac{4 \pm \sqrt{16 - 16}}{2}\\t_{1,2} = \frac{4}{2} = 2](https://tex.z-dn.net/?f=-t%5E2%20%2B%203t%20%3D%20-t%20%2B%204%5C%5Ct%5E2%20-%203t%20-%20t%20%2B%204%20%3D%200%5C%5Ct%5E2%20-%204t%20%2B%204%20%3D%200%5C%5Ct_%7B1%2C2%7D%20%3D%20%5Cfrac%7B-%28-4%29%20%5Cpm%20%5Csqrt%7B%28-4%29%5E2%20-%204%2A1%2A4%7D%7D%7B2%2A1%7D%20%3D%20%5Cfrac%7B4%20%5Cpm%20%5Csqrt%7B16%20-%2016%7D%7D%7B2%7D%5C%5Ct_%7B1%2C2%7D%20%3D%20%5Cfrac%7B4%7D%7B2%7D%20%3D%202)
The height of the objects are the same after 2 seconds.
Answer:
43
Step-by-step explanation:
Let
The unit digit = x
The tens digit = y
The number = 10x + y
The tens digit of a two-digit number is five more than the units digit.
y = x + 5
Seven times the sum of the digits of this number is 3 less than the number itself.
7(x + y) = 10x + y - 3
7x + 7y = 10x + y - 3
Find the number.
We substitute x + 5 for y
7x + 7(x + 5) = 10x + (x + 5) - 3
7x + 7x + 35 = 10x + x + 5x - 3
14x + 35 = 11x + 5x - 3
Collect like terms
35 + 3 = 11x + 5x -14x
38 = 16x - 14x
38 = 2x
x = 38/2
x = 19
Solving for y
y = x + 5
y = 19 + 5
y = 24
The number = 19 + 24
= 43
Answer:
It is 4
Step-by-step explanation: