Answer:
Commutative Property for Multiplication
I think the answer is -7.8
Answer:
The 5th day must be 90
Step-by-step explanation:
The first 4 days averaged out to 80
You can find their total just by multiplying by 4. That won't tell you the exact values, but it will tell you their total when you add the 4 of them together.
80*4 = 320
Now you need to add another day into the mix. Call it x
320 + x
Now there are 5 days, not 4, and the new total is 82.
(320 + x) / 5 = 82 Multiply both sides by 5
5*(320 + x) / 5 = 82 *5
320 + x = 410 Subtract 320
-320 -320
x = 90
Answer:
120
240
Step-by-step explanation:
We call the length of first part x
Length of second part = y
In the first scenario, it took the tortoise 110 sec to walk the first part and crawl the second.
So,
We have this equation,
x/4 + y/3 = 110
We take the LCM
(3x + 4y)/12 = 110
When we cross multiply
3x + 4y = 110x12
3x + 4y = 1320 ----- equation 1
For scenario 2
x/3 + y/4 = 100
When we take the LCM
(4x + 3y)/12 = 100
We cross multiply
4x + 3y = 100x12
4x + 3y = 1200 ------ equation 2
We now have two equations and we will solve for x and y using simultaneous linear equation.
3x + 4y = 1320 ----- 1
4x + 3y = 1200 ----- 2
We subtract equation 2 from 1 to get
- x + y = 120
We make y subject
y = x + 120 ----- 3
We put the value of y in equation 3 into equation 1
3x + 4(x + 120) = 1320
3x + 4x + 480 = 1320
7x + 480 = 1320
7x = 1320-480
7x = 840
We divide through by 7
x = 840/7
x = 120
We put value of x in equation 3
y = x + 120
y = 120 + 120
y = 240
120 and 240 are the lengths of the 2 parts of the journey.
Thanks
<span>seventy-seven hundredths.</span>
