twice meas. of supp. of angle is 39 less than 5 times comp.

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kjennings

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Twice the measure of the supplement of an angle is 39 degrees less than five times the complement of the angle. What is the measure of the angle? (Hint: Let 180 – x represent the supplement and 90 – x represent the complement.)
I have tried 180-2x=5x-39
I have tried 180-2x=90-39-5x
I can't get thr right answer which is 17 degrees
 
Hi kjennings:

You might have been thinking "twice the supplement of x", but your equations simply show "twice x".

kjennings said:
Twice the measure of the supplement of an angle ... Let 180 – x represent [this] supplement ...
Click to expand...

If the supplement of the angle x is 180 - x, then twice this amount is 2(180 - x).

You made the same type of mistake with the expression representing the complement.

Knowing this, can you correct your mistakes now? If not, then please let us know.

Cheers,

~ Mark :)
 
Hi again:

That's okay. Here's how to set up the equation.

You want to find the value of angle x.

180 - x is an expression for "the supplement of angle x".

90 - x is an expression for "the complement of angle x".

Here's the relationship you are given:

Twice the measure of the supplement of an angle is 39 degrees less than five times the complement of the angle.

Twice the measure of (180 - x) is 39 degrees less than five times (90 - x).

2(180 - x) = 5(90 - x) - 39

Please let us know if you need help solving this equation.

Cheers,

~ Mark :)
 
kjennings said:
I tried 5(90-x)-39
90-5x-39
Click to expand...

Hi kjennings:

5(90 - x) - 39 does NOT equal 90 - 5x - 39.

When you multiply (90 - x) by 5, you need to multiply both the 90 and the x by 5.

5*90 - 5*x - 39

450 - 5x - 39

This type of multiplication method is an example of the distributive property of operations. It follows this pattern:

a(b - c) = a*b - a*c

Cheers,

~ Mark

My edits: added missing quotation from original poster and fixed ambiguous language
 
You were told to solve this for x:
2(180 - x) = 5(90 - x) - 39

next: 360 - 2x = 450 - 5x - 39

If you can not finish that, then you may need in-person classroom help.
 
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