Raina, josh, and shen sent a total of 148 text messages during the weekend. shen sent 4 times as many messages as raina. josh sent 10 more messages than raina. how mant messages did they each send?

if raina=x

josh=y

shen=z

you have that

z=4x

y=x+10

x+y+z=148

solve the system and the results are

x=23

y=33

z=92

So, the equation I got was y = -7x -15.

Firstm you gotta find the slope using the slope formula, m = (y2-y1) / (x2-x1) (plug in the two initial points you were given, (7,-2) and (8,5). After you get the slope, which I got as -7, plug that into the y=mx+b formula with your last point (-3,6)
So, 6= -7(-3) + b -7 = m, -3 = x, 6 = y. after you solve the equation you should get -15. plug that into the y=mx+b formula andyou have your final equation,
y = -7x -15. to check if all of the point are on this equation, I'd recommend plugging the equation into the demos graphing calculator, it really helps. Hopefully this helped you!