tolong jawab pakai cara ya. makasih...

QBC+BQR=180
(4x-4)+(2x+7)=180
6x=180+4-7
x=177/6
x=29,5

CBD=180-(4x-4)
=180-(4*29,5 -4)
=180-(118-4)
=180-114
=66
[C]

180 = 4x - 4 + 2x + 7
180 = 6x + 3
180-3 = 6x
177 = 6x
177 : 6 = x
29,5 = x

<CBD = <RQB
<CBD = 2x + 7
<CBD = 2 × 29,5 + 7
<CBD = 59 + 7
<CBD = 66° (c)