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.
Depo-Provera is injected in to the muscle of your butÂ­tock. The injection will prevent pregnancy for three months and the birth control effects begin as soon as you have your first shot. The injection should be repeated every three months (11-15 weeks) as long as birth control protection is wanted.