tolong jawab nomor 3-5 ! besok dikumpul , please bantuuuu

3. HB = 100/110 . 880.000
= 800.000

4. y/10 = 6/10
y = 10 . 6/10
y = 6

5. 2a + 10 + a + 20 = 90
3a + 30 = 90
3a = 90 - 30
3a = 60
a = 60/3
a = 20
sudut CBD = 2a + 10 = 2 . 20 + 10 = 40 + 10 = 50

3. 10/100×880.000
= 88.000
Harga beli= 880.000-88.000
=792.000

5.a+20+2a+10=90
3a+30= 90
3a=90-30
3a=60
a = 20

CBD= 2a+10
=2×20+10
=50