Use the recursive formulae (derived from chebyshev polynomials)
ta+1(x) = 3t,(7) – (1 - 12u (2)
un+1(i) = tn (2) + xun(1)
to find t5(x) and u5(x) given that t0(x)=1 and u0(x)=0.

a is the correct

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.

just get this app called photo math it should be able to do those