When taking square roots, you can't take square roots of negative roots of negative numbers. So, what will work for the domain of u(x) is what makes u(x) zero or more. We can make an inequality for that.
u(x) ≥ 0.
9x + 27 ≥ 0 by squaring both sides
9x ≥ -27
x ≥ -3
So the domain of the function is when x ≥ -3 is true.
Answer:
"In word" as in word form?
3/4 = three fourths
1/5 = one fifth
3/4 = three fourths (again?)
1 3/5 = one and three fifths
Answer:
Step-by-step explanation:
We can solve this question using proportion
Perimeter of the square/Time is takes to unlock
We are told in the question that:
The cellphone unlocks when the perimeter reaches 32 centimeters, taking a total of 2.5 seconds.
Hence, the perimeter of the square after 1.5 seconds is:.x = unknown
32/2.5 = x/1.5
Cross Multiply
2.5x = 32 × 1.5
x = 32 × 1.5/2.5
x = 19.2 centimeters
Step-by-step explanation:
the answer is in the above image
Answer:the third option is correct
Step-by-step explanation:
The system of equations are
y = 2x^2 - 5x - 7 - - - - - - - - - - -1
y = 2x + 2 - - - - - - - - - - - - - 2
We would equate equation 1 and equation 2. It becomes
2x^2 - 5x - 7 = 2x + 2
2x^2 - 5x - 2x - 7 - 2 = 0
2x^2 - 7x - 9 = 0
We would find two numbers such that their sum or difference is -7x and their product is - 18x^2. The two numbers are 2x and - 9x. Therefore
2x^2 + 2x - 9x - 9 = 0
2x(x + 1) - 9(x + 1) = 0
2x - 9 = 0 or x + 1 = 0
2x = 9 or x = - 1
x = 9/2 = 4.5
Substituting x = 4.5 or x = -1 into equation 2, it becomes
y = 2 × 4.5 + 2 or y = 2 × - 1 + 2
y = 11 or y = 0
Therefore, the solutions are
(4.5, 11) (- 1, 0)
