Answer:
DCB = 78°
Step-by-step explanation:
A straight line is 180° so the angles ACD and DCB must add up to 180° so: 4x+2+3x+3=180
From here it's normal algebra, add like terms so it will be 7x+5=180
subtract 5 from both sides so it will be 7x=175
Divide both sides by 7 so we will get X=25 but we aren't done yet! We need to substitute the value of X into the angle DCB so we can get the real value so:
3(25)+3=78
Hope I helped!
