Please explain with solving mathematically linear equation and graph both

Suppose you have been hired by a research firm trying to understand the market for Widgets (a hypothetical product). Your analysis of the data indicates that the Demand curve for Widgets is estimated to be linear and given by equation Qd = 200 SP and the Supply curve for Widgets appears to be linear as well and is estimated as Q3 = 5P 50. Graphically draw these two curves, labeling all relevant points (such as intercepts for each line) on the horizontal and vertical axes