You can choose to expand the equation to find the coefficient of x7 but that would take a lot of time. Here is a useful tactic that can help;
11C(something)(1)(x)⁷ ----> This gives the coefficient of x⁷
11C7(1)⁴(x)⁷ ----> You know that pascal's triangle is equal on both sides
11C7×1⁴ = coefficient of x⁷ (just ignore x⁷)
330x1⁴=330
This means that the coefficient of x⁷ is 330. You can double check by expanding the equation. If you do not understand what I did there, you can ask me how I got to the solution.
Hope I helped :)
49x^2 - 9 = 0
As there is no x term, we can pretty much guess we have a situation where we factlrise by something known aa difference of two squares, so to factorise it:
49 = 7^2
9 = 3^2
x^2 = (x)^2
so...
(7x - 3)(7x + 3) = 0
7x - 3 = 0 7x + 3 = 0
x = 3/7 x = -3/7
Answer:
Step-by-step explanation:
x=3
So go down and up then look it up on the web so you can look good in it that really helps