Linear equation - One variable. 1  A linear equation in one unknown x may always be rewritten. 2  If a â  0, there is a unique solution. 3  If a = 0, then, when b = 0 every number is a solution of the equation, but if b â  0 there are no solutions (and the equation is said to be inconsistent.)
How effective is the Depo shot? The birth control shot â Depo-Provera â is one of the most effective methods of birth control available. Each shot of Depo-Provera will protect you from pregnancy for 12 weeks. It works best when you get the birth control shot regularly, every 12 weeks. Fewer than one out of 100 women will get pregnant each year if they always use the birth control shot as directed. About six out of 100 women will get pregnant each year if they donât always use the birth control shot as directed.
The birth control shot (such as Depo-Provera). Advantages. 1  Needed only every 13 to 14 weeks. 2  Reduces risk for endometrial and ovarian cancer. 3  Reduces symptoms of endometriosis.