how to find x in a angle that equals 90 degrees

Question

I was doing this problem and setting it up the way the last tutor told me to but now there is one that is a decimal! now do I se. up (4x+8) degrees and 46? the equation 46=4x+8 is what gets me the decimal. what am I doing wrong!?

Answer 1

You have two angles that add up to 90 degrees.

 

∠1 = 4x+8 degrees

∠2 = 46 degrees

 

∠1 + ∠2 = 90 degrees

 

4x+8+46 = 90

4x + 54 = 90

4x = 36

  x = 9

 

If we substitute this value into ∠1, we have

 

4(9)+8 = 44

 

44 degrees + 46 degrees = 90 degrees