Please help me I'm at my wit's end my tablet very slow and comes back

Hi everyone,

I purchased this Asus memo pad 7 inch for my mum for first time tablet second hand for Xmas, It's been having several issues from day one and I have factory reset it 4 times and updated it too but still no joy, here's goes, sometimes when pushing the on off button it won't turn on also I've been getting these weird lines from the top of the tablet to the bottom and blinking too, also it's very very slow at trying to load onto anything even with having a speed of over 6mbps the touchscreen becomes unresponsive to and the worst of all everytime I try to load any apps including Google its comes up with a message not responding wait report or close . Im a novice at technology so thought I would ask yous experts if yous could kindly help me please would be much appreciated. Especially with being my disabled mother first tablet and she can't even turn it on to try and start to learn what this big world of the web is all about. God love her she thought she broke it because she couldn't even turn it on. I do hope I have gave you enough information regarding this matter. Many thanks for your help and advice and reply in advance.

Kind regards