Answer:
x=-1
Step-by-step explanation:
A + b + c = 180
a = 2b
b = c + 4
Substitute the b equation into the a equation
a = 2(c + 4)
a = 2c + 8
Substitute equations a and b into the first equation
2c + 8 + c + 4 + c = 180
4c = 168
c = 42
Find the other angles using c
b = 42 + 4
b = 46
a = 2(42) + 8
a = 92
Therefore angle a is 92 degrees, angle b is 46 degrees, and angle c is 42 degrees.
X = amount of 90% alloy
y = amount of 70% alloy
x + y = 60
0.9x + 0.7y = 0.85*60
0.9x + 0.7(60 - x) = 0.85*60
(0.9 - 0.7)x = (0.85 - 0.7)*60
x = (0.85 - 0.7)*60/(0.9 - 0.7)
x = 45 ounces
y = 60 - 45
y = 15 ounces