Answer:
560x^3y^4.
Step-by-step explanation:
The (r+1)th term of (a + b)^r = nCr a^(n-r) b^r
We want the fifth term so r = 5 - 1 = 4:
(4 + 1)th term = 7C4 x^(7-4) (-2y)^4
= 35x^3 16y^4
= 560x^3y^4.
