Question

I️ need help with the your turn part

Answer 1

Because the angle is a straight angle, it means that the total of DEC and CEF would be 180º. (CEF + DEF = 180º) With this information we can make the equasion:

(11x - 12) + (2x + 10) = 180

first, to find x:

to simplify (11x - 12) + (2x + 10) = 180, you add the two equations:

13x - 2 = 180

13x = 182

x = 182/13

x = 14

Now, insert the x (which we found that is 14) to each equation.

DEC: (11 x 14 - 12)

= 154 - 12 = 142

m DEC is 142º.

CEF: (2 x 14 + 10)

=28 + 10 = 38

m CEF is 38º.

check: (CEF + DEC = 180º)

38 + 142 = 180

therefore, the answers are correct :D