Complete the next steps using the distributive property
please help me

a.
98 · 24
(100 - 2) · 24
2400 - 48 = 2352
b.
21 · 15
(20 + 1) · 15
300 + 15 = 315
c.
0.51 · 40
(0.5 + 0.01) · 40
20 + 0.4 = 20.4