What equation is equivalent to 3x+4y=15

Aline has a slope of 1/4 and passes through point (0.4,-1/2). what is the value of the y-intercept?

The length of the line segment joining the midpoints of sides ab and bc of the parallelogram abcd is 10. find the length of diagnol ac

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.