plis tolong dong yang no 18 yaaaa

5x + 3 + 3x + 7 = 90
8x + 10 = 90
8x = 90 - 10
8x = 80
x = 80/8
x = 10

CBD = 3x + 7
CBD = 3.10 + 7
CBD = 30 + 7
CBD = 37 derajat

Semoga membantu dan semofa bermanfaat...

(5x+3)+(3x+7)=90
8x+10=90
8x=80
x=8
sudut<cbd=3x+7=3(8)+7=24+7=31