Experts plz answer this question

Experts plz answer this question 22. on the set {0, 1, 2, a, 4, 5, 61, a binary operation defined as : if a 4b < 7 a + b —7, if a + b 27 Write the operation table Of the operation * and prove that zero is the identity fbr this operation and each element a 0 of the set is invertible with 7 — a being the inverse of a. 16 9 Find the maximum area Of an isosceles triangle inscribed.in the ellipse with its vertex at one end of the major axis. 16 9 y) x2 + Y2 4, x + y > 21 Find the area of the region y) : + 4, x + y 21, using the method of integration.