All estimating problems make the assumption you are familar with your math facts, addition and multiplication. Since students normally memorize multiplication facts for single-digit numbers, any problem that can be simplified to single-digit numbers is easily worked.
2. You are asked to estimate 47.99 times 0.6. The problem statement suggests you do this by multiplying 50 times 0.6. That product is the same as 5 × 6, which is a math fact you have memorized. You know this because
.. 50 × 0.6 = (5 × 10) × (6 × 1/10)
.. = (5 × 6) × (10 ×1/10) . . . . . . . . . . . by the associative property of multiplication
.. = 30 × 1
.. = 30
3. You have not provided any clue as to the procedure reviewed in the lesson. Using a calculator,
.. 47.99 × 0.6 = 28.79 . . . . . . rounded to cents
4. You have to decide if knowing the price is near $30 is sufficient information, or whether you need to know it is precisely $28.79. In my opinion, knowing it is near $30 is good enough, unless I'm having to count pennies for any of several possible reasons.
Answer:
The value of AB is ![\left[\begin{array}{ccc}21\\11\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D21%5C%5C11%5Cend%7Barray%7D%5Cright%5D)
and it's not possible to multiply BA.
Step-by-step explanation:
Consider the provided matrices.
![A=\left[\begin{array}{ccc}2&3\\2&1\end{array}\right]](https://tex.z-dn.net/?f=A%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%263%5C%5C2%261%5Cend%7Barray%7D%5Cright%5D)
, ![B=\left[\begin{array}{ccc}3\\5\end{array}\right]](https://tex.z-dn.net/?f=B%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%5C%5C5%5Cend%7Barray%7D%5Cright%5D)
Two matrices can be multiplied if and only if first matrix has an order m × n and second matrix has an order n × v.
Multiply AB
Matrix A has order 2 × 2 and matrix B has order 2 × 1. So according to rule we can multiply both the matrix as shown:
![AB=\left[\begin{array}{ccc}2&3\\2&1\end{array}\right] \left[\begin{array}{ccc}3\\5\end{array}\right]](https://tex.z-dn.net/?f=AB%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%263%5C%5C2%261%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%5C%5C5%5Cend%7Barray%7D%5Cright%5D)
![AB=\left[\begin{array}{ccc}2\times 3+3\times 5\\2\times 3+1\times 5\end{array}\right]](https://tex.z-dn.net/?f=AB%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%5Ctimes%203%2B3%5Ctimes%205%5C%5C2%5Ctimes%203%2B1%5Ctimes%205%5Cend%7Barray%7D%5Cright%5D)
![AB=\left[\begin{array}{ccc}6+15\\6+5\end{array}\right]](https://tex.z-dn.net/?f=AB%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D6%2B15%5C%5C6%2B5%5Cend%7Barray%7D%5Cright%5D)
![AB=\left[\begin{array}{ccc}21\\11\end{array}\right]](https://tex.z-dn.net/?f=AB%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D21%5C%5C11%5Cend%7Barray%7D%5Cright%5D)
Hence, the value of AB is
Now calculate the value of BA as shown:
Multiply BA
Matrix B has order 2 × 1 and matrix A has order 2 × 2. So according to rule we cannot multiply both the matrix.
We can multiply two matrix if first matrix has an order m × n and second matrix has an order n × v.
That means number of column of first matrix should be equal to the number of rows of second matrix.
Hence, it's not possible to multiply BA.
27 yd2 (b•h) it’s just like a rectangle
Answer:
The answer is 2
Step-by-step explanation:
3/4÷ 3/8 =
3 × 8 * 4 × 3 =
24/12 =
<u>24 ÷ 12</u>
12 ÷ 12 = 2
Answer:
The sum of two numbers is 14 and their difference is 10
Step-by-step explanation:
"2 numbers (x and y)
x+y = 14
and x-y + 10
If you each equation by positive 2, one gets 2x+2y = 28 and 2x-2y = 20
The 'y-terms' cancel out or equal zero when adding, so 4x = 48, divide by 4 on each side and x or the first number equals 12.
Plug 12 back into the equation for 'x' and subtract 12 on both sides so that y=2
The difference of 12-2=10 and the addition of 12 and 2 equals 14"
hopes this helps
