comparing the relation given
thus y= -2x +1 to the general equation of a line
where y= mx + c
where m is the gradient and c is the intercept on the y-axis.
from the question, the gradient is -2 and since the line is perpendicular, the gradient is given as

so substituting the value of m in to the equation

=

as the gradient
equation of line is given by
y - y1 = m( x-x1)
from the question y1= -2 and x1=1
substitute them
y-(-2) = 1/2 (x -1)
y+2 =1/2 (x-1)
multiplying through by 2
2 (y+2) = x-1
2y +4 = x-1
2y =x-1-4
2y =x-5
x -2y -5 = 0
therefore the equation for the line is x-2y -5=0
<span>The question is asking us to calculate how many envelopes are there in 7 packages if there are 75 in a package. For example: in 1 package there are 75 envelopes. In 2 packages there are 7 * 2 = 150 envelopes. In general, formula is : 75 * n, where n is the number of packages. Therefore, we will multiply 75 by 7. 75 * 7 = 525. Answer: B ) 525 envelopes.</span>
Point A=-1.3
Point B= 1.3
These 2 points are reciprocals, which means that their sum is Zero. So basically they are exact opposites.