What is the rule for finding the coordinates of an image reflected over the line y=-x?

What number must you add to complete the square x^2+12x=16

Tomas is making trail mix using granola and walnuts. he can spend a total of $12 on the ingredients. he buys 3 pounds of granola that costs $2.00 per pound. the walnuts cost $6 per pound. he uses the equation to represent the total cost, where x represents the number of pounds of granola and y represents the number of pounds of walnuts. he solves the equation for y, the number of pounds of walnuts he can buy. answer- b tomas added 6 to both sides of the equation instead of subtracting 6. just took the test

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?