You can use Pythagreos theorem to determine it!
Pythagreos theorem is a^2 + b^2 = c^2
1) 4^2 + 4^2 = 6^2
16 + 16 = 36
32 = 36 (So this is not a right-angled triangle )
2) 16^2 + 12^2 = 20^2
256 + 144 = 400
400 = 400 (Sp this is a right-ngled triangle)
By rounding $24.97 to $25, she actually added 3 cents to the price of the shirt. After adding $25 + $13.75 and getting $38.75, she needs to subtract the 3 cents she added to find the exact sum which is $38.72.
Answer: A. Subtract $0.03
Let's consider an arbitrary 2x2 matrix as an example,

The columns of

are linearly independent if and only if the column vectors

are linearly independent.
This is the case if the only way we can make a linear combination of

reduce to the zero vector is to multiply the vectors by 0; that is,

only by letting

.
A more concrete example: suppose

Here,

and

. Notice that we can get the zero vector by taking

and

:

so the columns of

are not linearly independent, or linearly dependent.
40min*1.05=42min they spent 42 min together
ps: check the multiplication it's 01:30 and I did that in head
A two-digit number is twice the sum of its digit. If the tens digit is 7 less than the unit digit, find the number.
Let x= the unit digit
Then y= the tens digit
<span>And 10y+x= the number
</span>x+y= the sum of the digits
<span>Now we are told that 10y+x=2(x+y) ------1st equation </span>
<span>We are also told that y=x-7 ----------- 2nd Equation </span>
<span>So our equations to solve are: </span>
(1) 10y+x=2(x+y)
<span>(2) y=x-7
</span>
Hope it helps