I understand the problem

c.100

Step-by-step explanation:

first draw a figure of rhombus EFGH to avoid confusions

given

angle E= 3x+5

angle H= 4x

here,

E=G and H=F ( opposite angles of rhombus are equal)

now,

E+G+H+F= 360 ( sum of interior angles in a rhombus)

3x+5+3x+5+4x+4x= 360

x= 25°

we know that,

F= H

F= 4x

F= 4 × 25

F= 100

let m = monomial

let t = trinomial

so, m times t = t.

monomial times a trinomial = another trinomial.