Urgent Resultant force maths question plsss help!!

2.5 N force is acting at angle 'x' (theta).If you resolve the force vertically then F= 2.5 cos x and horizontallly 2.4 = 2.5 sin x.
This gives us sin x = 24/25
If 2.4 force is removed then only force left horizontally is horizontal component of 2.5 N which is 2.5 sin x = 2.5 × 24/25 = 2.4 N
Since movement is in horizontal direction this is equal to m.a
Therefore m.a = 2.4 N

Thank you! So just to check, the vertical component of 2.5 is balanced by F so when the 2.4 force is removed, the resultant force is the 2.4N which is the horizontal component of F and that is the resultant force?

I was also trying to attempt this question: https://app.gemoo.com/share/image-annotation/639108670275133440?codeId=v67gqQNnpd3Jl&origin=imageurlgenerator
But i was unsure how to resolve it? We don’t know the angle between 6N and the ground or 10N and the ground so i didn’t know how to split it into the horizontal and vertical components? I was even more confused when the marscheme used the angle 70 to resolve, I didn’t know where they got that from? Please could i have some help, thank you so much!!!

You can use the cosine formula to solve it
C²= a²+b² - 2 ab Cos c where Cos C is Cos 110
and a= 10 and b=6

I used that but they said that the angle isn’t 110, it’s 70?

My bad: it is 70 degree actually. I did not pay attention to direction of vector. If you move the 6N vector so that it's tail touches the tip of 10 N vector then angle becomes 180-110= 70 degrees.
Use
C²= a²+b²-2ab cos 70
If you do not want to move the 6N vector then you have to consider it's magnitude as negative
C²= a²+b²- 2 a (-b) cos 110
Where B = 6N and a =10 N

Thank you, but im quite confused on how this changes? As in normally we have to resolve vertically and horizontally to find the resultant force but here we are joining the two vectors up?

Resolving vertically and horizontally is the preferred method and you should always do that if you have the angle between the vector and the axis/plane. In this particular question you have an angle between 2 vectors. You can still resolve it vertically and horizontally but the method is long and complex. These kind of questions are rare and would mostly ask for resultant force between the two. If in a question you have to find acceleration/ tension/ velocity then it would be a straightforward horizontal and vertical component.