1.Explain the basic difference between the two subsets of inference rules. Derive the conclusion from the given premises for the 4 exercises below. (NB: these are extracted mainly from textbook Exercise 4-8 except the last one.) [43-2] C: ~B P1: A & (B -> C) P2: ~(C & A) [43-3] C: C P1: (A & B) V (C & D) P2: ~A [43-4] C: ~B P1: (A & B) -> C P2: A & ~C [43-5] (Hint: use Equiv to break P1, an equivalence, into a conjunction of 2 conditionals) C: ~U P1: (A & U) <-> ~R P2: ~(~R V ~A)

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk

the answer would be d

straight away you can eliminate a and c because not all books contain a scientific skill because some may be fiction. c is also wrong because it saids that the only way children can learn is through books which is incorrect.

b is also wrong because reading can be a scientific skill but not always, therefore it is wrong which leaves you with d, the correct answer since it said that it can children learn.

hope this ! : 3