Iam doing solving by elimination for algebra 1 and i am lost here is the question
-2x-3y=-13
-3x-2y=-2

Aculture started with 3000 bacteria. after 5 hours it grew to 3900 bacteria. predict how many bacteria will be present after 9 hours

Which shows the correct substitution of the values a,b and c from the equation 1=-2x+3x^2+1

Mrs. gehrke said cheddar weighs 16.8 pounds. he actually weighs 15.2 pounds. what is the percent error?