B.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
If a line's slope is

, the slope of the perpendicular line is

in this case, the given line has a slope 4, which is 4/1, so the perpendicular line has a slope/gradient
If you slowly increase the strength of an electric current flowing through the wire, you would expect the magnet to become stronger. The correct option among all the options that are given in the question is the first option or option "a". The magnetic field around the wire becomes stronger. I hope it helps you.
Answer:

Step-by-step explanation:
Isolate the variable, a. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
PEMDAS is the order of operation and stands for:
Parenthesis
Exponents (& Roots)
Multiplication
Division
Addition
Subtraction
First, add 3 to both sides of the equation:
u = -3a - 3
u (+3) = -3a - 3 (+3)
u + 3 = -3a
Next, divide -3 from both sides of the equation:
(u + 3)/-3 = (-3a)/-3
a = (u + 3)/-3
is your answer.
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