Answer: 16
Step-by-step explanation:
Let:
x = Chemistry textbooks sold
y = Physics textbooks sold
The textbook store sold a combined total of 260, so:

The number of chemistry books sold was three times the number of physics textbooks sold, so:

Let:

Replace (2) into (1):

Replace the value of y into (2):
The answer is 75° because all three angles of a triangle must add to 180°
The answer would be 10^-3
Answer:
x = 5 y =-2
Step-by-step explanation:
You can substitute the 4y in,
7x - (-3-x) = 43
7x + 3 + x = 43
8x + 3 = 43
8x = 40
x = 5
Then plug the x back into the equation,
4y = -3 - 5
4y = -8
y = -2