Answer:
Two straight lines with slopes m and m' are parallel when m = m'
Two straight lines with slopes m and m' are perpendicular when m × m' = - 1.
Step-by-step explanation:
Let us assume that the two non-vertical lines in the slope-intercept form are
y = mx + c ........... (1) and
y = m'x + c' ............ (2)
If those two lines are parallel then we can say the slope of them will be the same i.e. m = m'
Now, if given two straight lines (1) and (2) are perpendicular to each other and neither of them is parallel to the axes, then we can write m × m' = - 1. (Answer)
I'll give a practice problem to help explain it a bit better.
Here, let's try to solve 45% of of 60.
First, we convert the percentage into a decimal. To turn any percentage into a decimal you move the point two spaces to the left.
That means 45% as a decimal is .45.
Next, we multiply our number, 60, by the decimal .45.
60×.45=27.
That means 45% of 60 is 27.
To sum it all up, you have to get the percentage, move the decimal point two spaces to the left, and multiply it by the number you were trying to find the percentage of.
Have a wonderful day! :)
(10/n +6) -3
10/2+6-3
5+6-3
11-3
8
Hope this helped!
D because if you multiply y 8 times it will no longer be doubling the area
