tolong bantu saya mengerjakan soal nomer 16-22

16.) x1 + x2 = -b:a
=-(-8):4
=2 (A)
17.) x1 × x2 = c:a
= 10:4
= 5:2 (B)
18.) xkuadrat - 7x + 10 = (x-2) (x-5)
x-2=0 atau x-5=0
x=2 atau x=5 (C)
19.) x + 15derajat + 4x = 180derajat
5x + 15derajat = 180derajat
5x = 180 - 15
x = 165 : 5
= 33 derajat (A)
20.) 120 : 72 × 30 = 50derajat
21.) 270per360 × 22per7 × 42 = 99 cm(A)
22.) pnjngbambu yg dmliki 4,6m = 460cm
kerangka balok = 4 (p+l+t)
= 4 (10+5+8)
4 (23) = 92
banyak balok = 460 :92 = 5 balok (C)