(4x+5)(4x-5) is equal to 16x^2+20x-20x-25
The positive and negative 20x cancel out
Leaving you with: 16x^2 - 25
[S/N this is a pattern that shows up a decent amount. Whenever you have something that looks like (x^2-y^2) it factors out to (x+y)(x-y). It might be helpful to remember]
The next one, (4x+5)2, just follows the distributive property. Multiply both components within the parentheses bye the coefficient of 2: 8x+10
Answer: 60
Step-by-step explanation:
Find the total number of students.
In this case, there are 8 total students. Multiply 60 * 8 = 480
Add all the numbers up.
85 + 65 + 36 + 48 + 75 + 39 + 72 = 420
480 - 420 = 60
x = 60
Answer:
4.75
Step-by-step explanation:
u×t=5 +1/2×-2×1/2²