Eighty nine crore, six lakh, seventy eight thousand and three hundred forty.
Two lines are perpendicular if and only if the product of their slopes is - 1.
So, you just need to find the slope of each line and find out the product of their slopes.
I will do one example for you.
L1: y = 3x + 5
L2: y = - 3x + 14
L3: y = -x/3 + 14
The slope of a line is the coefficient of the x.
So the slopes are:
L1: slope 3
L2: slope -3
L3: slope -1/3
So now multiply the slopes of each pair of lines:
L1 and L2: 3 * (-3) = - 9 => No, they are not perpendicular
L2 and L3: (-3) * (-1/3) = 1 => No, they are not perpendicular
L1 and L3: (3) * (-1/3) = -1 => Yes, they are penpendicular.
Answer/Step-by-step explanation:
Recall: 
a. 
b. 
c. 
<span>In
the fairest school 20% are below 16 years old
1/3 are teachers which is equals to = 21
Let’s start solving:
=> 1/3 of 100% = ( 100 / 3 = 33.33% )
thus 33.33% = 21
=> 21 x 3 = 63, is the total number of people in the school.
Let’s try solving the number of people below 16 years old
Then there are 20% of it:
=> 63 * .20 = 12.6
Thus, there are around 13 people who are 16 years old younger.</span>