<h3>
Answer: D) 7</h3>
===================================================
Explanation:
a31 means "the value in the third row, first column". That value is 7
As another example, a22 = 3 since 3 is in the second row, second column.
Another example: a12 = -1 because we're in the first row and second column.
This is a 3x2 matrix due to it having 3 rows and 2 columns.
Obtuse, if that’s what you mean.
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.
Find the perimeter of the scale artwork
P=2(l+w)
P=2(2.5+1.75)
=2(4.25)= 8.5 in
1 in = 0.5 ft
8.5in = 0.5(8.5)
=4.25ft = 51 in
the actual perimeter is 51 in or 4.25 ft
