Answer:
So the Point of intersection is (-4,-2)
Which is option A
Step-by-step explanation:
The given system of equations is
-0.1x - 0.8y = 2 ...................(i)
0.6x - 0.5y = -1.4 ...................(ii)
Let us take equation (i) and use method of substitution for solving it
the equation (i) is
-0.1 x - 0.8y = 2
Adding 0.8y on both sides
-0.1 x + 0.8 y - 0.8 y = 2 + 0.8 y
-0.1 x = 2 + 0.8 y
Dividing both sides -0.1

x = -8 y - 20 ..........................(iii)
Now we will use this value and put it into equation (ii) to find the value of y
Equation (ii) is
0.6 x - 0.5 y = -1.4
Put value of x
0.6(-8 y - 20) - 0.5 y =-1.4
It becomes
-4.8 y - 12 - 0.5 y = -1.4
adding 12 on both sides
-4.8 y - 0.5 y - 12 + 12 = -1.4 + 12
it becomes by solving
-5.3 y = 10.6
Dividing both sides by -5.3

So
y = -2
Now we have the value of y putting it in equation (iii)
Equation (iii) is
x = -8 y - 20
Putting value of y
x = -8*(-2) - 20
x = 16-20
x=-4
So the Point of intersection is (-4,-2)
Its c because you have to add all those numbers and it equals c
Idk if this really helps, but I put them into Desmos (free graphing thing) and this popped up
The solutions you get when you solve the formula are the corresponding y coordinates to your x value. So say a point on your graph is (2,3). The first number is x and the second is y. (x,y). The number you plug into your function is x,or in this case: 2. The solution to the equation when the x value is plugged in is y, or 3. Therefore, giving you a point on your graph.
Marty read 4 times as many pages as Nelson and Jennifer COMBINED. Marty read 1,860 pages.
In total, after dividing Marty's total by 4, Jennifer and Nelson both read a total of 465 pages.
After subtracting Nelson's 240, Jennifer is then found to have read 225 pages.
B would be the best viable option, as it clearly shows that 240+?x4=1,860, which it does.
Hope this helped. Khan Academy is a great resource for any learner. :)