Answer:
x = 14
Step-by-step explanation:
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FACTS TO KNOW :-
- Linear Pair is a pair of adjacent angles on a straight line whose sum is 180°
- All linear pairs are supplementary angles (because their sum is 180°) but all supplementary angles are not linear pairs.
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In the question , the given angles are supplementary angles because both (3x)° & (7x + 40)° are adjacent to each other and they are on a straight line.
As they are supplementary angles , their sum will be 180°.
So ,
[tex](3x) + (7x + 40) = 180[/tex]
[tex]=> 3x + 7x + 40 = 180[/tex]
[tex]=> 10x + 40 = 180[/tex]
Substracting 40 from both the sides ,
[tex]=> 10x + 40 - 40 = 180 - 40[/tex]
[tex]=> 10x = 140[/tex]
Dividing both the sides by 10 ,
[tex]=> \frac{10x}{10} = \frac{140}{10}[/tex]
[tex]=> x = 14[/tex]
