If they intersect they have the same x and y values so we can say y=y which can be expressed as:
-7x/8+1/4=-3x/4+1/2 make all terms have a common denominator of 8
-7x/8+2/8=-6x/8+4/8 now multiply all terms by 8
-7x+2=-6x+4 add 6x to both sides
-x+2=4 subtract 2 from both sides
-x=2 divide both sides by -1
x=-2, now we solve for y using either original equation...
y=-3(-2)/4+1/2
y=6/4+1/2
y=6/4+2/4
y=8/4
y=2 so the lines intersect at the point:
(-2, 2)