Answer:
C=13
Explanation:
Ok, so those to angles are going to equal 90*.
First, you wan to setup your equation,
(2c-4) + (5c+3) = 90
now you want to add the angles
7c -1 = 90
isolate the variable .
Add 1 to both sides
7c=91
Now divide 7 from both sides
c=13.
To check our work we will plug in for C.
2(13)-4 + 5(13)+3=90
26 - 4 + 65 + 3=90
90=90