Question

1. find the value of x.

Explanation:

Step1: Find angle ADC

$\angle ADC = 180^\circ - 120^\circ = 60^\circ$
(Linear pair supplementary)

Step2: Sum angles in triangle CDB

$\angle ADC + (15x+5) + (22x+4) = 180^\circ$
(Triangle angle sum property)

Step3: Simplify and solve for x

$60 + 15x + 5 + 22x + 4 = 180$
$37x + 69 = 180$
$37x = 111$
$x = 3$

Answer:

3