Answer would be 140 why does my answer need to be 20 words long ugh
When two lines cross like this, sum of measures of opposite angles is 180.
this means that:
measure angle AEC + measure angle BED = 180
4x-40 + x+50 = 180
5x +10 = 180
5x = 170
x = 34
therefore:
measure angle AEC = 4x-40 = 4(34)-40 = 96
measure angle BED = x+50 = 34+50 = 84
B........................
Answer:
A
Step-by-step explanation:
Basically, this is an observational study because the researcher does not apply any treatment.
It's not an experiment because there is no experimentation involved. :)
It's not double-blind because in that case the researcher would have to apply something to two kinds of groups. one aware one the other not. not the case.
It's not D because The observations are comparing two kinds of subjects and they are not looking for a cause and effect.
It costs $189-(4×$20) which is $189-$80=$109