On a laptop with no mouse, can you zoom on the x or y axes one at a time, separately?
I've found clicking on the plot, then using the touchpad allows you to only zoom both axes simultaneously, even if you press the shift or control keys.
Not sure about your laptop but on my Windows desktop if you click on the plot there are 3 dark squares that appear at the bottom of the y axis, right of the x axis and in the lower right hand corner. By grabbing one of those you can stretch the plot in the y, x or equally y and x.
Also if you grab the intersection of x and y axis you can shift the plot left, right, up or down.