Which is the equation of a line that is perpendicular to the line represented by y=7/6x+4

Lines that are perpendicular will have slopes that are opposite reciprocals. The slope of y=7/6x+4 is 7/6. So we need to find the opposite reciprocal of 7/6. Opposite would make the number negative and reciprocal would switch the numerator with the denominator. So the slope of any line reciprocal to y=7/6x+4 would be -6/7. Then you can use any real number as the y intercept for the new equation.
An acceptable answer would be
y= -6/7x+10
But the number 10 could be replaced by any real number.

The surface area would be 576 because you multiply all the numbers then multiply that number by 6