7m is all that you should be left with. Are you just trying to isolate your variable?
Answer:
A. 90 sq. units
Step-by-step explanation:
5(18) = 90
let the first angle be a
then
second angle= 68+a
third angle=2a
we know
a+b+c=180 [sum of interior angle of triangle is 180]
a+68+a+2a=180
4a=180-68
a=28
Hence
first angle=28
second angle = 96
third angle =56