Find out the angle of a certain vector?!

Given that
A=2i + 3j
and
B=3i - 4j
find the angle of
C=A+B

please write all the steps and formulas to calculate the above numerical clearly.thanks in advance

Adding the two vectors we have C = 5i - j

tan θ = -1/5 .

Hence θ = -11.3°, below the i axis.
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You can add the components in the i and j directions separately:

2i + 3i = 5i

3j + (-4j) = -j

So the final vector C = 5i - j

The angle can be found using tan (theta) = -1/5, so inverse tan (-1/5) = -9 degrees (that is, 9 degrees below the j axis)

C= 5 i + 7 j

angle tan x = 5/7

find x