First, multiply each side of the equation by #color(red)(u - 7)# to eliminate the fraction while keeping the equation balanced:
#color(red)(u - 7) * -2/(u - 7) = -8 * (color(red)(u - 7))#
#cancel(color(red)(u - 7)) * -2/color(red)(cancel(color(black)(u - 7))) = (-8 * color(red)(u)) + (-8 * color(red)(-7))#
#-2 = -8u + 56#
Next, subtract #color(red)(56)# from each side of the equation to isolate the #u# term while keeping the equation balanced:
#-2 - color(red)(56) = -8u + 56 - color(red)(56)#
#-58 = -8u + 0#
#-58 = -8u#
Now, divide each side of the equation by #color(red)(-8)# to solve for #u# while keeping the equation balanced:
#(-58)/color(red)(-8) = (-8u)/color(red)(-8)#
#(-2 * 29)/color(red)(-2 * 4) = (color(red)(cancel(color(black)(-8)))u)/cancel(color(red)(-8))#
#(color(red)(cancel(color(black)(-2))) * 29)/color(red)(color(black)(cancel(color(red)(-2))) * 4) = u#
#29/4 = u#
#u = 29/4#