Question 884575
for January we have two points (1, 10) and (31, 12)
For February we have two points (1, 12) and (28, 9)
slope(m) is (y2 - y1) / (x2 - x1)
slope for January is ((12 - 10) / (31 - 1) = 2/30 = 1/15
slope for February is (9 - 12) / (28 -1) = -3/27 = -1/9
equation of line for January is y = x/15 +b
use first January point 10 = 1/15 + b and b = 9.93
January line formula is y =x/15 +9.93 (red line graph)
equation of line for February is y = -x/9 +b
use first February point 12 = -1/9 + b and b = 12.11
February line formula is y = -x/9 + 12.11 (green line graph)
Here is a graph of both lines
{{{ graph( 300, 200, -40, 40, -20, 20, x/15 +9.93, -x/9 +12.11) }}}
You can see that there are two strait lines that intersect