Answer:
the dimension of the poster = 90 cm length and 60 cm width i.e 90 cm by 60 cm.
Step-by-step explanation:
From the given question.
Let p be the length of the of the printed material
Let q be the width of the of the printed material
Therefore pq = 2400 cm ²
q = 
To find the dimensions of the poster; we have:
the length of the poster to be p+30 and the width to be 
The area of the printed material can now be: 
=
Let differentiate with respect to p; we have

Also;

For the smallest area 


p² = 3600
p =√3600
p = 60
Since p = 60 ; replace p = 60 in the expression q =
to solve for q;
q =
q = 
q = 40
Thus; the printed material has the length of 60 cm and the width of 40cm
the length of the poster = p+30 = 60 +30 = 90 cm
the width of the poster =
=
= 40 + 20 = 60
Hence; the dimension of the poster = 90 cm length and 60 cm width i.e 90 cm by 60 cm.
A) is right
b) just subtract ljm and kjm so 145-48 = 92°
c) 9x-25=7x+7 so here you put npq=mpq+mpn and you combine terms so it's now 2x=32 then divide by 2 on both sides and x= 16
now you just plug it into 3x-5 and you get 43°
Rewriting the left-hand side as follows,

Assuming that the given shape is a cuboid,
volume=l×w×h
v=s³ (since cuboids have same length, they have same side length)
62=s³
∛62=s
s=3.957 ≈ 4 units
Hope I helped :)