Step-by-step explanation (work shown in attached picture):
1) Since x is already isolated in the first equation, substitute that value for x into the other equation to find y. So, substitute 16-4y for the x in 3x + 4y = 8, then solve for y. This gives us y = 5.
2) Now, substitute that given value for y back into any one of the equations to find x. I chose to do it in the first equation. Substitute 5 for the y in x = 16-4y, then solve for x this time. This gives us x = -4.
is a variable whose value will change depending on the value of another variable, called the independent variable. Dependent variables are also known as outcome variables, left-hand-side variables, or response variables.