Answer:
1
7 ✔️
15
21
Only 7 is a prime number in this question.
Answer:
x=-6
×=1
Step-by-step explanation:
remove parentheses
connect like terms
change the signs
calculate the discriminant
simplify
Remark
There is no short way to do this problem and no obvious way to get the answer other that to solve each part.
Solve
A
Multiply by 2
x + 1.6 = 2(x + 0.1) Remove the brackets
x + 1.6 = 2x + 0.1*2
x + 1.6 = 2x + 0.2 Subtract x from both sides
1.6 = x + 0.2 Subtract 0.2 from both sides
1.6 - 0.2 = x
1.4 = x
Circle A
B
Subtract 2x from both sides.
3x - 2x = 1.4
Circle B
C
Remove the brackets.
4x + 6 = 2x - 6 Add 6 to both sides
4x + 12 = 2x Subtract 4x from both sides.
12 = -2x Divide by - 2
12/-2 = x
x = - 6 Don't circle C
D
I'm going to be very scant in my solution of this. You can fill in the steps.
3x = 4.2
x = 4.2/3
x = 1.4
Circle D
The reflex angle is the other angle
see image below
so
reflex=360-angle
reflex=360-60=300
reflex angle=300
Given:
The power generated by an electrical circuit (in watts) as function of its current x (in amperes) is modeled by:

To find:
The current that will produce the maximum power.
Solution:
We have,

Here, leading coefficient is negative. So, it is a downward parabola.
Vertex of a downward parabola is the point of maxima.
If a parabola is
, then

In the given function, a=-12 and b=120. So,



Putting x=5 in the given function, we get




Therefore, 5 watt current will produce the maximum power of 300 amperes.