tolong dijawab dgn caranyaa

lt=lo(1+koefisien muai panjang×∆t)
30.04=30(1+1.9×10-5×∆t)
30.04÷30=1+1.9×10-5×∆t)
0.04=1.9×10-5×∆t
∆t=0.04÷1.9×10-3(jika koefisienya m dirubah ke cm)
∆t=21
∆t=t2-t1
t1=100-21=79