Any number, either positive or negative raised to the power of 0 is equal to 1.
x +y = 20 ( rewrite as x = 20-y)
3x - 3y =30
3(20-y) - 3y = 30
60-3y - 3y = 30
60-6y = 30
-6y = -30
y = -30 / -6 = 5
x=20-5 = 15
x = 15, y = 5
Answer:
x=50
Step-by-step explanation:
x in (-oo:+oo)
(2/5)*x+10 = 30 // - 30
(2/5)*x-30+10 = 0
2/5*x-20 = 0 // + 20
2/5*x = 20 // : 2/5
x = 20/2/5
x = 50
x = 50