Answer: 15
a=5, b=3
3a= 3x5= 15
Equation of a straight line is normally in the form: y = mx + c.
Where, m and c are constants in which;
m = gradient
c = y-intercept.
Comparing this standard way way of writing the equation of a straight line with the current scenario, this equation can be rewritten as;
y = b1x + b0.
This way, b1 = gradient of the line while b0 = y-intercept.
Circumference; C = π2r
Diameter; D = 2r
So then ...
C = πD
7.38 = πD
7.38 / π = D
2.35 cm = D
I think it’s b I hope this help