ini gimana ya cara hitungnya??

no 2.
nilai a=2
nilai b=2a=10
nilai c=ab
=2×10=20
nilai a+b+c
=2+10+20
=32

no3.
matriks A
=2×(-1)–0×1
= -2-0
= -2
matriks B
= -1×(2)–0×(1)
= -2-0
= -2
nilai A–2B
= -2-2×(-2)
= -4×(-2)
= 8