Frank stars by taking 10 steps forward from a position 5 steps behind where he started, so he's 10-5= <<10-5=5>>5 steps forward in total
Frank then takes 2 steps back, meaning he's now 5-2=<<5-2=3>>3 steps forward in total from where he began
He then takes double the previous amount of 2 steps forward, so he takes 2*2= <<2*2=4>>4 steps forward
Since Frank was 3 steps forward before that, that means Frank finishes 3+4=<<3+4=7>>7 steps forward
#### 7