Choice D : look at where you think the line would be if it followed the direction of the data so that about half of the points fell above the line and half below. The two most important things to note are the slope of the line and y intercept. This is a negative relationship as the line falls as you read it from left to right. That eliminates choice C. Next, it appears the line of best fit would have a y intercept around 10 on the y axis and then fall down and to the right cutting the data. Note that choices A and B have y intercepts that don't make sense for the data. Choice D does have a y intercept of 10 and a negative slope.
We suggest this system of equations: x+y=7 (10y+x)=(10x+y)+9 we solve it by substitution method. x=7-y 10y+(7-y)=(10(7-y)+y)+9 9y+7=70-10y+y+9 9y+10y-y=70+9-7 18y=72 y=72/18=4
Substitute first Y for the second Y So it would be x + x + 6 = -2 Then it would be 2x +6 = -2 Move the 6 over so it would be 2x =-8 Divide by 2 your answer is x = -4
