Question

If three angles (3x-7)°, 55°, (x+20°) makes a linear pair then find x​

Answer 1

Answer:

∠AOD+∠DOC+∠COB=180

∘

[linear pair]

3x+10+3x+10+2x=180

8x+20=180

8x=180-20

8x=160

x=

8

160

=20

∴ value of x is 20.

Answer 2

Given Info : -

• Three angles (3x-7)°, 55°, (x+20°) makes a linear pair.That means –
• The First angle be (3x - 7)°
• The Second angle be 55°
• The Third angel be (x + 20)°

Explanation:-

We are asked to find –

• Value of x.

We know that –

• The sum of all the angles in a linear pair is equal to 180°.

$\purple{\bigstar \; {\underline{\boxed{\bf{ Sum _(Angles) =180° }}}}}$    

$\longrightarrow \tt (3x - 7)° + 55° + (x + 20)° = 180°$

$\longrightarrow \tt 3x° - 7° + 55° + x° + 20° = 180°$

$\longrightarrow \tt 3x° + x° - 7 + 55° + 20° = 180°$

$\longrightarrow \tt 4x° - 7° + 55° + 20° = 180°$

$\longrightarrow \tt 4x° - 7° + 75° = 180°$

$\longrightarrow \tt 4x° - 68° = 180°$

$\longrightarrow \tt 4x° = 180° + 68°$

$\longrightarrow \tt 4x° = 248°$

$\longrightarrow \tt x° = \cancel{\dfrac{248}{4}}$

$\longrightarrow \tt{\pink{\underline{\underline x = 62°}}}$

• Therefore, Value of x is 62°.

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