The -1 means move one place, but because there is a minus sign in front of it, this time we move one place to the left, along the x axis. The second number in the brackets relates to the y axis.

Left axis deviation occurs when the QRS axis falls between -30 and -90. There are a variety of causes, including left anterior fascicular block and left ventricular hypertrophy. See the ECG basics ...

As you move along a line from left to right, you might go up ... The \(y\)-intercept is 3 because the line crosses the \(y\)-axis at (0, 3). So the equation of the line in the form \(y = mx ...