$ 1 U.S. dollar = 0.76 euros
so $ 30 U.S. dollars = (30 * 0.76) = 22.8 euros <==
In a triangle, the total angle is 180 degrees. A straight line is always 180 degrees. With this in mind, the following can be obtained:

These are simultaneous equations.

Answer:
x = -11
Step-by-step explanation:
Hello There!
create an equation
x + 51 + 60 + 80 = 180
combine like terms
51 + 60 + 80 = 191
x + 191 = 180
subtract 191 from each side
180 - 191 = -11
we're left with
x = -11
Answer:
X = 9, -1
Step-by-step explanation:
1, Factor it
(x-9) (x+1) = 0
2. Both of a factor will = 0
x-9 = 0
x+1=0
3. Solve
x=9
x=1