I've worked these problems but I was just wondering if someone could check over them to see if they're correct...if not please help!
(u-2)(u+7)
my answer: 7u^2-49u
(5t-4)^2
my answer: 25t^2-40+16
Thank you :)
hmm, well use either FOIL or the distributive property. I will use distributive property:
(u-2)(u+7)
my answer: 7u^2-49u
-----------------------
u(u+7) -2(u+7)
u^2 + 7u - 2u - 14
=
u^2 + 5 u - 14
===============================
25t^2-40+16
You forgot a t
25t^2-40t+16
Sure, I'd be happy to help! Let's go through each problem and check if your answers are correct.
1. (u-2)(u+7)
To simplify this expression, we can use the FOIL method. FOIL stands for First, Outer, Inner, Last.
Multiply the First terms: u * u = u^2
Multiply the Outer terms: u * 7 = 7u
Multiply the Inner terms: -2 * u = -2u
Multiply the Last terms: -2 * 7 = -14
Now, combine all the terms:
u^2 + 7u - 2u - 14
Simplifying further, we can combine like terms:
u^2 + 5u - 14
So, the correct answer for (u-2)(u+7) is u^2 + 5u - 14.
2. (5t-4)^2
To square this binomial expression, we can use the identity (a-b)^2 = a^2 - 2ab + b^2.
Plugging in the values from the given expression:
(5t)^2 - 2(5t)(4) + (4)^2
Simplifying further:
25t^2 - 40t + 16
So, the correct answer for (5t-4)^2 is 25t^2 - 40t + 16.
I hope that helps! Let me know if you have any further questions.