Respuesta :

Answer:

[tex] \huge{ \boxed{ \bold{ \tt{46 \degree}}}}[/tex]

Step-by-step explanation:

Given :

  • [tex]\sf{m \angle \: A \: = \: (2x + 30)°} [/tex]
  • [tex] \sf{ \: m \angle \: B \: = (7x - 3)°}[/tex]

To find :

  • [tex] \sf{measure \: of \angle \: B} \: = ? [/tex]

Solution :

Remember that the sum of complementary angles is always 90°.

First, finding the value of x :

Set up an equation :

[tex] \sf{(2x + 30) + (7x - 3) = 90°}[/tex] ( Being complementary angles )

Solve for x

[tex] \sf{⇢2x + 30 + 7x - 3 = 90°}[/tex] { Remove unnecessary parentheses }

[tex] \sf{⇢9x + 30 - 3 = 90°}[/tex] { Combine like terms }

[tex] \sf{⇢9x + 27 = 90°}[/tex] { Subtract 3 from 30 }

[tex] \sf{⇢ \: 9x = 90° - 27}[/tex] { Move 27 to right hand side and change it's sign }

[tex] \sf{⇢ \: 9x = 63°}[/tex] { Subtract 27 from 90}

[tex] \sf{⇢ \: \frac{9x}{x} = \frac{63°}{9}} [/tex] { Divide both sides by 9 }

[tex] \sf{⇢ \: x = 7°}[/tex]

The value of X is 7°

Now, Replacing the value of x in order to find the value of [tex] \angle[/tex] B

[tex] \sf{(7x - 3)°}[/tex]

[tex] \sf{⇢ \: (7 \times 7 - 3)°}[/tex] { Plug the value of x }

[tex] \sf{⇢ \: (49 - 3)°}[/tex] { Multiply 7 by 7 }

[tex] \sf{⇢ \boxed{46°}}[/tex] { Subtract 3 from 49 }

The measure of [tex] \angle[/tex] B is 46°

And we're done!

Hope I helped!

Best regards! :D

~TheAnimeGirl