<u>Answer:</u>
The correct answer option is B. 2 = 3x + 10x^2
<u>Step-by-step explanation:</u>
We are to determine whether which of the given equations in the answer options can be solved using the following expression:
Here, 
and 
.
These requirements are fulfilled by the equation 4 which is:
Rearranging it to get:
Substituting these values of 
in the quadratic formula:
Elga's age = x
Alvin's age = x + 7
x + x + 7 = 97.
Simplify the left side of the equation
2x + 7 = 97.
Subtract 7 from each side
2x = 90.
Divide each side by 2
x = 45
Since x is equal to Elga's age, Elga is 45 years old
Answer:
Below
Step-by-step explanation:
sin(2x) = 2 ×cos(x)× sin(x)
● sin(x) = 2 × cos(x) × sin(x)
● 2 × cos(x) = 1
● cos (x) = 1/2
So we can deduce that:
● x = Pi/3 + 2*k*Pi
● or x = -Pi/3 + 2*k*Pi
K is an integer
The system of equations has one solution
