Answer: {11, -11}
Step-by-step-explanation: To solve for <em>x</em> in this equation, since <em>x</em> is squared, we simply take the square root of both sides of the equation to get <em>x</em> by itself.
It's important to remember however that when taking the square root of both sides of an equation, we always use <em><u>plus</u></em> or <em><u>minus</u></em>.
In other words in this problem, since x² = 121,
<em>x = + or - 11</em>.
A common mistake is to say that <em>x</em> is just equal to 11. But notice that if you plug a -11 back into the original equation, it also checks.
So our answer to this problem is {11, -11}.
Answer:
200 + 5x, where x is the amount of days.
Step-by-step explanation:
You start out with 200, which is your base number, and is not going to change because at the beginning of March, it was already installed. Since 5 new phones are being added everyday, you get 5x.
Answer:
see explanation
Step-by-step explanation:
Given A is directly proportional to r² then the equation relating them is
A = kr² ← k is the constant of proportion
To find k use the condition when r = 5, A = 75 , then
75 = k × 5² = 25k ( divide both sides by 25 )
3 = k
A = 3r² ← equation of proportion
(a)
when r = 4, then
A = 3 × 4² = 3 × 16 = 48
(b)
when A = 147 , then
147 = 3r² ( divide both sides by 3 )
49 = r² ( take the square root of both sides )
r = = 7
Answer:
Tom will run 9 miles in 12 minutes.
Step-by-step explanation: