Question

Help with some math please!!!!!

!!!!
1.In △ABC, m∠A=(4x+7)° and m∠B=(5x−3)°.

What is m∠B?


3.Find the value of x.

Answers are

A.24

B.12

C.35

D.117

Answer 1

B. 12

Step-by-step explanation

The given triangle is isosceles, because two of the arms are equal.

The angles directly under these two arms and the base are equal.

Therefore the three angles of the isosceles triangle are

84°, 4x°,4x°

The sum of these angles is 180°

`84 + 4x + 4x = 180`

`84 + 8x = 180`

Group similar terms,

`8x = 180 - 84`

`8x = 96`

Divide both sides by 8

`x = 12`

The correct choice is B.