2x(x+4)-1(x+4)
2x^2+8x-x-4
2x^2+7x-4
There are no numbers that when multiplied get 8 and when added get 3.
Thus, you will have to use the Quadratic Formula.
<h3>hello!</h3>
Let the number be x.
subtract 4:-
x-4 (4 less)
this expression equals 9:-
x-4=9 (Option C)
<h3>note:-</h3>
Hope everything is clear; if you need any explanation/clarification, kindly let me know, and I will comment and/or edit my answer :)
S is a subset of U, so all of the elements of S must be also elements of U
If U was {letters}, 4, 9, ? would not belong there
If U was {numbers }, x, y, ? would not belong to U
If U was {punctuation marks }, 4, 9, x, y would not be in U
all the elements of S are in U={ keys on a keyboard}
Answer: U={ keys on a keyboard}