Help, I don’t understand

13°

Step-by-step explanation:

Since these are complementary angles, we can add them together, set it equal to 90, and solve for x:

[Equation] (-6x + 53)° + (-9x + 22)° = 90°

[Distribute] -6x° + 53° + -9x° + 22° = 90°

[Combine like terms] 15x° + 75 = 90°

[Subtract 75 from both sides] 15x° = 15

[Divide both sides by 15] x = 1°

Then, plug-in our x for angle ADC:

[Given] (-9x + 22)°

[Distribute] -9x° + 22°

[Subsititue / plug-in] -9(1)° + 22°

[Multiply] -9° + 22°

[Combine like terms] 13°

Have a nice day!

     I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)

- Heather

i do not know this sorry : (