Answer:
[tex]-32x^5+320x^4-1280x^3+2560x^2-2560x+1024[/tex]
Step-by-step explanation:
We must expand [tex](-2x+4)^5[/tex] using the Binomial Theorem.
To do so, we need Pascal's Triangle. Seeing that the exponent is 5, we look at the 5 + 1 = 6th row of Pascal's Triangle. The numbers here are:
1, 5, 10, 10, 5, 1
These will be the numbers to multiply all the distinct terms in the expansion by.
Remember that when expanding this out, we always start by taking the first term (-2x here) to the nth power (here, it's 5th power) and multiplying that by the second term (4 here) to the 0th power:
(-2x)^5 * 4^0 = -32x^5 * 1 = -32x^5
Since this is our first term, we multiply it by the first Pascal number from above: 1. Then, we simply get -32x^5 as our final first term of the expansion.
We repeat this process, each time lowering the first power by 1 and increasing the second power by 2.
2nd term:
(-2x)^4 * 4^1 = 16x^4 * 4 = 64x^4
Multiply by 5:
64x^4 * 5 = 320x^4
3rd term:
(-2x)^3 * 4^2 = -8x^3 * 16 = -128x^3
Multiply by 10:
-128x^3 * 10 = -1280x^3
4th term:
(-2x)^2 * 4^3 = 4x^2 * 64 = 256x^2
Multiply by 10:
256x^2 * 10 = 2560x^2
5th term:
(-2x)^1 * 4^4 = -2x * 256 = -512x
Multiply by 5:
-512x * 5 = -2560x
6th term:
(-2x)^0 * 4^5 = 1 * 1024 = 1024
Multiply by 1:
1024 * 1 = 1024
Hence, our expansion is:
[tex]-32x^5+320x^4-1280x^3+2560x^2-2560x+1024[/tex]
