Because the ones place is under 5, we round down, and 392 becomes 390 when rounded to the nearest 10
Y=-x+8
gradient of the parallel line is the same as the gradient of the line given, which is -1
to find the y-intercept, sub the values (9,-1) into the equation we are finding which is y=-x+c
Subtract 17from both sides
32-17=x
Simplify 32-17 to 15
X=15
