Me! it’s math! i don’t understand this .

To solve the system of equations below, grace isolated the variable y in the first equation and then substituted into the second equation. what was the resulting equation? 3y=12x x^2/4+y^2/9=1

Evaluate 3(a + b + c)squared for a = 2, b = 3, and c = 4. a. 54 b. 243 c.729 add solution .

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?