84 in I believe? (Im sorry im not much help)
Answer :
C
Explanation:
It is C because it simplifies down to 5x+5x.
98+(3x-17)=180
81+3x=180
180-81=3x
3x=99
x=33
Answer:
Option D
x+4x>55
Step-by-step explanation:
Let the age of Julio be x
The age of Julio's father will be 4x
The sum of their ages is
x+4x
The sum is no less than 55 to mean it's greater than 55 hence
x+4x>55
We know that, as per a corollary of intermediate value theorem, if a function f(x) is continuous on a closed interval [a,b], and values of f(a) and f(b) have opposite signs, then the function f(x) is guaranteed to have a zero on the interval (a,b).
So, basically, we need to figure out two values of x, at which the values of the given cubic function have opposite signs.
Let us consider the interval [-2,1].
We have . Upon substituting the values x=-2 and x=1 one by one, we get:
We can see that signs of values of the function at x=-2 and x=1 are opposite, therefore, as per intermediate value theorem, the function is guaranteed to have a zero on the interval [-2,1]