500? If you're trying to find x...
The answer is b because it is b
Answer:(d): y=ax+b (a≠0); (d1)y=-4x+13
because of (d)⊥(d1) --> a.(-4)=-1 --> a=
(d): y=
+b. (d) pass through P(-1;-2) so we have
-2=(1/4).(-1)+b ---> b=
(d) y= 
1600<2570-125.5x<2000 subtract 2570 from all terms...
-970<-125.5x<-570 divide all terms by -125.5 (and reverse signs because of division by a negative!)
7.73>x>4.54 and x is months since January, and since months can only be integers...
x=[5,7]
So January + 5, 6, and 7 respectively are the three months that satisfy the equation...
June, July, and August.
I'm not sure what you mean by difference, so I am guessing you meant to write "distance". If this is not the case, then feel free to report me. Anyway, to find the distance between two points you would use the distance formula.
Distance Formula:
.
Let's substitute our point coordinates into the formula. We'll substitute -1 and 6 for x_2 and x_1, and 14 and 16 for y_2 and y_1. After substituting, your formula will now look like:
.

Subtract the coordinates.

Square the subtracted coordinates.

Add 49 and 4.

Square root 53 and round the answer to the nearest tenth.
7.28 becomes 7.3.
7.3 units is the distance between points M and Z.