Question

How would I answer this?

Answer 1

Answer:

C = 145.4°

By creating a system of equations (2 equations) with the information from a problem, we can substitute and solve for the missing variables.

Step-by-step explanation:

Linear pairs are found on a straight line, so they total to 180°.

C + D = 180 ......eq'n [1]

C is seven more than four times D can be represented with this equation:

C = 4D + 7 ........eq'n [2]

We can solve by substituting [2] into [1], replacing "C".

C + D = 180

4D + 7 + D = 180

Collect like terms

5D + 7 = 180

Subtract 7 from both sides

5D = 173

Divide both sides by 5

D = 173/5

As a decimal, D = 34.6°.

Using eq'n [2], find C. Substitute the value of "D". Solve.

C = 4D + 7

C = 4(173/5) + 7

C = (692/5) + 7

C = (692/5) + (35/5)         Find a common denominator.

C = (692+35)/5                Combine into numerator.

C = 727/5

As a decimal, C = 145.4°.