(x + y)8, if x = 0.3 and y = 0.7, what is the numerical value of the third term?

Possible Answers
0.010
0.020
0.058
0.060
0.068

Question

(x + y)8, if x = 0.3 and y = 0.7, what is the numerical value of the third term?

Possible Answers
0.010
0.020
0.058
0.060
0.068

welshfella · Answer

(x + y)^8  = x^8 +  8C1 x^7 y +  

can you continue?

anonymous · Answer

no i don't understand how to do it at all can you show me the steps

welshfella · Answer

yes this is the binomial theorem

first 3 terms of (x + y)^n

= a^n + nC1 x^(n-1) y ^ 1 + nC2 x^(n-2) y^2

so uou are interested in nC2 x^(n-2) y^2

so plug in the values of n, x and y and you have the answer