The process by which ova are surgically removed from a woman and then mixed with sperm to produce a zygote, which is then inserted into the uterus, is called

In vitro fertilization (IVF)

Explanation:

In patients undergoing IVF Follicle stimulating hormone (FSH) is administered at levels that are higher than naturally occurring to cause a controlled over stimulation of the ovaries, so that they ultimately produce multiple eggs ( FSH ripens follicles of the ovaries that release estrogen, each follicle contains one egg and on average only one follicle becomes fully mature).  The eggs are then retrieved just before ovulation and the sperm samples are produced by masturbation.  In the lab the eggs are prepared for fertilization in a petri dish.  Fertilization can occur by one of two techniques:

1.The eggs are incubated with thousands of sperm, and fertilization occurs naturally over a few hours.

2.The second technique maximizes certainty of fertilization by using a needle to place a single sperm inside the egg (used when there is a problem with the quality of the sperm).

After fertilization, embryos are delivered into the woman’s uterus via catheter.  The embryo is transferred 3 days after fertilization when the embryo has eight cells or on day five when an embryo is called a blastocyst and has hundreds of cells.

To increase the odds of success, doctors sometimes transfer multiple embryos at once, which is why IVF results in twins and triplets more often than natural pregnancy.  

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)