The total angle sum of a triangle is 180°
As such, 180= 78 + 2s +4s
102= 6s
s=17
I'm attaching the solution.. feel free to ask if you have questions.. I basically did long division. Hope this helps.
Since you have the answers given, just track their walking.
After one hour, one guy has covered 3mi and the other 4mi, which is in total 7, not 14
After 2 hours, one guy has covered 6mi and the other 8mi, which is 14mi
The algebraic way would be:
3x +4x = 14 *x being the hour
7x = 14
x =2
The slope is the factor in front of x, so slope is 9.
The y intercept is 7 (that's the point of cross the y axis, where x=0)
There are multiple definitions of "standard form" for lines, so here are the two i can think of:
9x - y = -7 (the implicit function form)
or
y-7 = 9*(x-0) (the point-slope form)
Lmk if you have questions.
