Answer: x = 3
Step-by-step explanation: both expressions are equal to each other because the angles are opposite of each other, so you would set the expressions equal to each other and solve from there.
set equations = to each other: 6x - 7 = 4x - 1
add 7 to the other side: 6x = 4x + 6
subtract 4x to the other side: 2x = 6
divide both sides by 2: x = 3