# How do you evaluate the definite integral int (5x)dx from [0,3]?

The value is $\frac{45}{2}$
${\int}_{0}^{3} 5 x \mathrm{dx} = 5 {\int}_{0}^{3} x \mathrm{dx} = \frac{5}{2} {x}^{2} {|}_{x = 0}^{x = 3} = \frac{45}{2}$