Question 391303
x-y=16_x=4y-5

Since -y does not contain the variable to solve for, move it to the right-hand side of the equation by adding y to both sides.
x=y+16_x=4y-5

Replace all occurrences of x with the solution found by solving the last equation for x.  In this case, the value substituted is y+16.
x=y+16_(y+16)=4y-5

Remove the parentheses around the expression y+16.
x=y+16_y+16=4y-5

Since 4y contains the variable to solve for, move it to the left-hand side of the equation by subtracting 4y from both sides.
x=y+16_y+16-4y=-5

Since y and -4y are like terms, add -4y to y to get -3y.
x=y+16_-3y+16=-5

Since 16 does not contain the variable to solve for, move it to the right-hand side of the equation by subtracting 16 from both sides.
x=y+16_-3y=-16-5

Subtract 5 from -16 to get -21.
x=y+16_-3y=-21

Divide each term in the equation by -3.
x=y+16_-(3y)/(-3)=-(21)/(-3)

Simplify the left-hand side of the equation by canceling the common factors.
x=y+16_y=-(21)/(-3)

Simplify the right-hand side of the equation by simplifying each term.
x=y+16_y=7

Replace all occurrences of y with the solution found by solving the last equation for y.  In this case, the value substituted is 7.
x=(7)+16_y=7

Remove the parentheses around the expression 7.
x=7+16_y=7

Add 16 to 7 to get 23.
x=23_y=7

This is the solution to the system of equations.
x=23_y=7