Question

Q=400-2P+4i and Q=100+30

Answer 1

At Equilibrium; Quantity supplied = Quantity Demanded

$400-2P+4i=100+3P$

Assuming i=25

Then

$400-2P+4*25=100+3P$

$400-2P+100=100+3P$

$500-100=3P+2P$

$400=5P$

$P=80$

$Q=400-2(80)+100$

$Q=340$