K-12=28...? I think this is what your question is asking for
Answer:
1. 3/5
2. 9/20
3. 1/5
4. 9/10
Step-by-step explanation:
<em>Find Slope:</em>
y = -x + 3
slope = -1
Perpendicular slope = 1
<em>Sub Slope into Equation </em>
y = mx + c
Found that m = 1 (slope = 1)
y = x + c
<em>Find C</em>
At (-1,3)
3 = (-1) + c
c = 3 + 1
c = 4
<em>Sub C into the equation </em>
y = x + 4
The equations above are all in the format

, where

= the gradient, or slope.
So, in the first question,

, the gradient would be 4, because 4 is

in this equation (the number before the

).
The gradient of a line perpendicular to this line is equal to the negative reciprocal of the gradient of the line. A better way to explain it is if

= the gradient of the line and <u />

= the gradient of the perpendicular line then:

So in the first question, the gradient of the perpendicular line is

.
Divide 4.92 by 12. that's 0.41. each card is priced less than a dollar at 0.41