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Need help with 7. and 8. Pleaseeee. Show your work.

Need help with 7. and 8. Pleaseeee. Show your work.-example-1

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Complementary angles are angles that add up to 90°

Supplementary angles are angles that add up to 180°

7.

So with our info, we can form the equation
3x-4+5x+6=90 to solve for x.

Firstly, combine like terms:
8x+2=90

Next, subtract both sides by 2:
8x=88

Lastly, divide both sides by 8 and x is going to be
x=11

Now that we have the value of x, plug that into both angles to solve for their degrees:


3*11-4\\ 33-4\\ 29\text{\textdegree}\\ \\ 5*11+6\\ 55+6\\ 61\text{\textdegree}

In short, ∠DEF is 29° and ∠FEG is 61°.

8.

With our info, we can form the equation as
9x+1+8x+9=180 to solve for x.

Firstly, combine like terms:
17x+10=180

Next, subtract 10 from both sides of the equation:
17x=170

Lastly, divide both sides by 17, and the x value is going to be
x=10

Now replace the x value with 10 to solve for the angles:


9*10+1\\ 90+1\\ 91 \text{\textdegree}\\ \\ 8*10+9\\ 80+9\\ 89\text{\textdegree}

In short, ∠DEF is 91° and ∠FEG is 89°

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