Answer:
y = - 10
Step-by-step explanation:
Given that y varies directly with x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 2 when x = - 4, that is
2 = - 4k ( divide both sides by - 4 )
= k, that is
k = -
y = - x ← equation of variation
When x = 20, then
y = - × 20 = - 10
Answer:
x = 5
Step-by-step explanation:
20(20-x)=300
1. Divide both sides by 20.
20(20-x)/20 = 300/20
2. Simplify.
20-x=15
3. Subtract 20 from both sides.
20-x-29=15-20
4. Simplify.
-x=-5
5. Divide both sides by -1.
-x/-1 = -5/-1
6. Simplify.
x=5
