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3x+8y=5, a line that can be written in the form of y=mx+c as y=(-3/8)x+5/8
because they are parallel then the gradient or slope are the same. Now, take another point (x,y) that the unknown line passes through. From the details it also passes through (5,7) and we've found the gradient to be -3/8.
formula for gradient= (y1-y2)/(x1-x2)=gradient
the two points (x,y) and (5,7) will help find the equation of the line;
cross multiply to get;
8y+3x=71 is the equation of the unknown line.
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