Answer:

Step-by-step explanation:
we know that
An exterior angle of a triangle is equal to the sum of the opposite interior angles.
see the attached figure to better understand the problem
so
∠DEF=∠ECD+∠CDE
substitute the given values

solve for x
Combine like terms

Group terms



Find the measure of angle CDE

substitute the value of x

Answer:217,000,000,000 (or just plain 217000000000)
Step-by-step explanation:7% is 0.07.
0.07 * 3.1 trillion
Divide the amount of teenagers that smoked by the total population:

Multiply this decimal by 100 to convert into a percentage:

To round to the nearest decimal place, look at the hundredths value:
8.5
3
3 > 5
8.53 -> 8.5
8.5% of teenagers reported that they smoked at least one cigarette.
36÷6 is 6 to show your work for it maybe draw it out and better show the equation like when you solve a bigger problem.
Answer:
Kate's electric bill will be $9 for this month for bulb use only.
Step-by-step explanation:
Given:
Electricity bill lass month from bulb use = $12
Using new bulbs percent decrease in electricity = 25%
We need to find this month electric bill for bulb use.
Solution:
First we will find the reduction in bill after using new bulbs.
reduction in bill after using new bulbs can be calculated by percent decrease in electricity using new bulb multiplied by last month Electricity bill from bulb use only.
framing in equation form we get;
reduction in bill after using new bulbs = 
Now we will find this month electric bill for bulb use only.
this month electric bill for bulb use only can be calculated by subtracting reduction in bill after using new bulbs from last month electric bill for bulb use only.
framing in equation form we get;
this month electric bill for bulb use only = 
Hence Kate's electric bill will be $9 for this month for bulb use only.