Why is -1 + 1= 0

thanks for the help

Because the negative and postive numbers cancel eacother out

idk why is -1 + 1 =0

Step-by-step explanation:

gotta hate on them ancient greeks they invented mathjk

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,

the answer is d

the answer is in the first quadrant, which make the y-int positive.

since the dots are going down, therefore the correlation is negative

i hope it is right.