Math question, please help​

Explanation:

Let's say that a = 25, b = 37 and c = 32 are the side lengths.

The uppercase letters A,B,C are opposite their lowercase counterparts.

That means angle A is opposite side a = 25

Apply the law of cosines to find angle A

a^2 = b^2 + c^2 - 2*b*c*cos(A)

25^2 = 37^2 + 32^2 - 2*37*32*cos(A)

625 = 1369 + 1024 - 2368*cos(A)

625 = 2393 - 2368*cos(A)

625 - 2393  = -2368*cos(A)

-1768  = -2368*cos(A)

-2368*cos(A) = -1768

cos(A)= (-1768)/(-2368)

cos(A) = 0.746621621621622

A = arccos(0.746621621621622)

A = 41.7014263373247

A = 41.7

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons