I'm trying to multiply this and keep getting the wrong answer:
(x - 5)(-0.025x + 220)
I have used the FOIL method and I have multiplied (x - 5) -0.025x and then multiplied (x - 5) 220.
Both methods I get the same answer.
But... the answer book and the teacher say it's -0.025x^2 + 219.875x - 1100.
My problem is that I don't get the 219.875x -- because when I multiply the -5 times -0.025x I get a positive number that adds up to 220x.
Could you tell me what I am doing wrong, please?
the book is wrong
I get -0.025x^2 + 220.125x - 1100
To correctly multiply two binomials, such as (x - 5) and (-0.025x + 220), you need to apply the distributive property. Let's break down the process step by step:
1. Start by multiplying the first terms of both binomials:
(x * -0.025x) = -0.025x^2
2. Next, multiply the first term of the first binomial with the second term of the second binomial:
(x * 220) = 220x
3. Now, multiply the second term of the first binomial with the first term of the second binomial:
(-5 * -0.025x) = 0.125x
4. Finally, multiply the second terms of both binomials:
(-5 * 220) = -1100
Now, let's combine these results to get the final answer:
-0.025x^2 + 220x + 0.125x - 1100
Combining like terms:
-0.025x^2 + (220x + 0.125x) - 1100
Simplifying further:
-0.025x^2 + 220.125x - 1100
So, the correct answer is -0.025x^2 + 220.125x - 1100.