Answer:

Step-by-step explanation:
<u>Equation of a line</u>
A line can be represented by an equation of the form

Where x is the independent variable, m is the slope of the line, b is the y-intercept and y is the dependent variable.
We need to find the equation of the line passing through the point (7,2) and is perpendicular to the line y=5x-2.
Two lines with slopes m1 and m2 are perpendicular if:

The given line has a slope m1=5, thus the slope of our required line is:

The equation of the line now can be expressed as:

We need to find the value of b, which can be done by using the point (7,2):

Operating:

Multiplying by 5:

Operating:

Solving for b:

The equation of the line is:

Answer:
Ihorangi uses 7.65 litres of petrol to and from work
Step-by-step explanation:
If the car Ihorangi drives consumes 7.5 L/100 km
Then for 1 km journey, the car will consume 7.5/100 L
= 0.075 L
If Ihorangi travels 51 km to work and 51 km from work
Therefore Ihorangi travel (51 + 51) km daily to and from work
= 102 km daily
The fuel he consumes daily is 102*0.075 L
= 7.65 L
Ralph's height is y
Ben's height is x
Ben's height is 1/20 of Ralph's height. How tall is Ralph?