75x+35≥7(11x+9)+475x+35≥7(11x+9)+4
75x+35≥77x+63+475x+35≥77x+63+4 [expand all blackets]
75x+35≥77x+6775x+35≥77x+67 [collect like terms]
−2x+35≥67−2x+35≥67 −2x≥32−2x≥32 [subtract 77x through]
x≤−16x≤−16
[subtract 35 through and divide through by 2]
Fractions they are easy REALLY!!

This result is actually true for any exterior angle. The exterior angle of a triangle is equal to the sum of the two remote angles, and above is a short proof of it.
Answer:
We use cosine rule also called cosine law which states
c^2=a^2+b^2-2abcosC
given
a=8cm, b=7cm, c=9cm cos C?
9^2=8^+7^2-2*8*7 cos C
expand
81=64+49-112 cos C
like terms together
81-113=-112 cos C
-32=-112cos C
multiply both sides by -1
32=112cos C
divide both sides by 112
32/112=cos C
cosC=0.2857
find cos inverse of 0.2857
angle C= 73.40
You have to keep order of operations in mind.
1. Take care of the parentheses; distribute.
-3+6x-3=-20-8x
Simplified: 6x-6=-20-8x
2. Isolate the x variable.
Add 8x to both sides and add 6 to both sides.
14x=-14
3. Solve for x.
Divide by 14 on both sides.
x=-1