the length of the radius of th dartboard is 9in. the diameter is represented by the expression 3x+3 write an equation that you cansolve for x then solve for x the x=5 but how do you work it out

diameter = 2*radius

diameter = 3x+3 = 2*9 = 18
x = 5

check

3*5+3 = 15+3 = 18 = 2*9