Step-by-step explanation:
x=y+9
substitute
3(y+9)+8y=-6
3y+27+8y= -6
13y = -6 -27
13y= -33
y = -33/13
x = -33/13 + 9
The first number will be 500
the second number will be 600
and the last number will be 990
Please find the attachment for a better understanding of the explanation to this question.
As we can see from the diagram attached, the X axis represented by XX' and the Y axis represented by YY' intersect each other at the origin represented by O. Further, we notice that this intersection is at the angle 90 degrees or in other words the intersection is perpendicular. Thus, we have seen that the the x and y axes in the xy plane intersect perpendicularly. And hence, the answer is TRUE.
Please note that this is always the case and this is also known as orthogonality.