Answer:
the value of x is 16
Explanation:
we know that the measure of angle ABC is 159deg.
we are told the angle ABF is (7x+20)deg
and that angle FBC is (2x-5) deg
the angle ABC is the same as adding angle ABF and FBC together
To find the value of x, add the two: (7x+20)+(2x-5)=159deg
When solving you will get 9x+15=159
subtract 15 from both sides and you will have 9x=144
divide both sides by 9 and you will be left with x=16