Equation of the straight line can be given in more form. The most common forms are implicit (general or standard) form ax+by+c=0 and explicit form y=kx+i, where k is line coefficient and l is cut which line made on the y axis. If k>0 then the angle that takes straight line with the positive direction to the x axis is sharp and if k<0 then the angle that takes straight line with positive direction to the x axis is obtuse. In you case you only need to form one monomial with variable y in the given equation in the following way: 3x-4y+7=3y => add to both side (-3y) and you get 3x-4y-3y+7=3y-3y finally we get implicit or general 3x-7y+7=0. If is it necessary to transform from the implicit into the explicit form we will do this in the following way: 3x-7y+7=0 add to both side expression (-3x-7) => 3x-3x-7y+7-7=-3x-7 => divide both side with (-7) => y= (-3x-7)/ (-7) => finally we get y=3/7 x + 1 ( in our case coefficient of direction k=3/7 and the cut which line is made3 on the y axis l=1). Its display in the decartes coordinate system is given in one of the already given answers.
That means that head was the most one to appear than tails
"He starts both trains at the same time. Train A returns to its starting point every 12 seconds and Train B returns to its starting point every 9 seconds". Basically, what you need to do is find the least common multiple. The least common multiple of 12 and 9 is 36, so the least amount of time, in seconds, that both trains will arrive at the starting points at the same time is 36 seconds.