Given:
.
To find:
The value of r.
Solution:
We have,
.
We know that the radius is perpendicular to the tangent at the point of tangency
AD is the tangent and CD is the radius. So, CD is perpendicular to AD at point D, i.e., 
.
Using Pythagoras theorem, we get
On further simplification, we get
Therefore, the value of r is 9.
The standard form equation for a straight line is y=mx+b where m is the slope and b is the y intercept. Substitute your given information:
y= -3/7x+2 is the equation
as you already know, a direct proportional variation has a constant of variation "k", y = kx, which in this case that'd be the slope, namely 15.
Ashton has saved: 60% of $120=(60/100)*$120=(60*$120)/100=$72
Ashton need to buy the bike=$120-$72=$48
He needs to buy the bike=$48
The surface area of the cube is 600cm^2.
6(10^2)
6(100)
600
