Answer:
Step 2: 20x = 80 + 10x
Step-by-step explanation:
Step 1: 20x - 10 = 80 + 10x
Add 10 to each side
20x - 10+10 = 80+10 + 10x
20x = 90 + 10x
Step 2: 20x = 80 + 10x This has the first error
Step 3: 10x = 80
Step 4: x= 8
Answer:
y-determinant = 2
Step-by-step explanation:
Given the following system of equation:
Let's represent it using a matrix:
![\left[\begin{array}{ccc}1&2\\1&-3\end{array}\right] = \left[\begin{array}{ccc}5\\7\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%262%5C%5C1%26-3%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D5%5C%5C7%5Cend%7Barray%7D%5Cright%5D)
The y‐numerator determinant is formed by taking the constant terms from the system and placing them in the y‐coefficient positions and retaining the x‐coefficients. Then:
![\left[\begin{array}{ccc}1&5\\1&7\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%265%5C%5C1%267%5Cend%7Barray%7D%5Cright%5D%20)
y-determinant = (1)(7) - (5)(1) = 2.
Therefore, the y-determinant = 2
Let's denote Cindy's age which is unknown with X
We know that Cindy's age is 3 times her age 6 years ago.
6 years ago Cindy's age was the present age (X) - 6 : X-6
The fact that the present age is 3 times her age 6 year ago can be written as:
3*(X-6)
So, finally:
X=3*(X-6)
Answer:
lower bound: 315 litres
upper bound: 324 litres
Step-by-step explanation:
The following rules apply:
- if the last digit of the number is 1, 2, 3, or 4; it is rounded down
- if the last digit of the number is 5, 6, 7, 8, or 9.
; it is rounded up
So:
314 is rounded to 310
315 is rounded to 320
324 is rounded to 320
325 is rounded to 330
