Answer:
see photo for detailed analysis
Step-by-step explanation:
Answer:
see explanation
Step-by-step explanation:
Given that M is directly proportional to r³ then the equation relating them is
M = kr³ ← k is the constant of proportion
To find k use the condition when r = 4, M = 160, thus
160 = k × 4³ = 64k ( divide both sides by 64 )
2.5 = k
M = 2.5r³ ← equation of variation
(a)
When r = 2, then
M = 2.5 × 2³ = 2.5 × 8 = 20
(b)
When M = 540, then
540 = 2.5r³ ( divide both sides by 2.5 )_
216 = r³ ( take the cube root of both sides )
r =
= 6
Answer:
180
Step-by-step explanation:
Answer:
b) Substitute (3x - 5) for y in the second equation.
Step-by-step explanation:
If using the substitution method, then the second choice is the most efficient first step.
<u>What is the substitution method?</u>
The substitution method can be used to solve a system of equations. It is when you isolate any of the variables from one of the equations and then substitute that value into the other equation.
Here, the first equation already has an isolated variable, y. We can then substitute its value into the second equation. Like so:
⇒ 2x + 6y = 20
⇒ 2x + 6(3x - 5) = 20
Learn more about the substitution method here:
brainly.com/question/27728118
brainly.com/question/26094713