The measurement of ∠B is 168°
Given,
In the question:
Angle A and Angle B are supplementary angles.
If mA (x - 9)° and m/B= (7x + 21)°
To find the measure of ∠B
Now, According to the question;
What are supplementary angles?
Two angles are Supplementary when they add up to 180 degrees.
Now, ∠A+∠B = 180°
So,
⇒(x - 9)˚+(7x + 21)°=180°
=> 8x +12 = 180°
=> 8x = 180° - 12
=> 8x = 168
=> x = 168/8
=> x = 21
For the measure of ∠B :
∠B = (7x + 21)
∠B = 7 x 21 + 21
∠B = 168°
Hence, The measurement of ∠B is 168°
Learn more about Supplementary angles at:
brainly.com/question/13045673
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I would use subsitution
y=x-7
sub x-7 for every x
5x+2(x-7)=14
5x+2x-14=14
add 14 to both sides
7x=28
divide both sides by 7
x=4
sub
y=x-7
y=4-7
y=-3
x=4
y=-3
(4,-3)
I mean, there is no decimal place, so you can’t determine to the nearest hundredth place.
For the hundreds place, it would round to 100, though.