so 5 people work each one for 21 minutes, that means 21+21+21+21+21 minutes altogether, namely 105 minutes, it took that long for 7 walls, hmmmm how long for just one wall then? well, 105 ÷ 7, namely 15 minutes then, for just 1 wall.
now, if it takes 15 minutes of work to do one wall, what about 5 walls? well, that'd be 15*5 or 75 minutes.
so if we have 3 folks working, how much would each one work? well, 75 ÷ 3, namely 25 minutes, so each of them will work 25 minutes, namely 25+25+25 minutes, so in 25 minutes, they'll be done with 5 walls.
Answer:
x = - 2, x = 9
Step-by-step explanation:
Given
f(x) = 
The denominator of f(x) cannot be zero as this would make f(x) undefined.
Equating the denominator to zero and solving gives the values that x cannot be.
x² - 7x - 18 = 0
(x - 9)(x + 2) = 0
Equate each factor to zero and solve for x
x + 2 = 0 ⇒ x = - 2
x - 9 = 0 ⇒ x = 9
The excluded values are x = - 2, x = 9
5.1 ANSWERS.pdf
2. Page 3. Practice: Use your calculator to sketch a graph of each
Answer:
A
Explanation: horizontal line is 180 degrees, and the square means 90 degrees. So adding up the angles z + 90 + z =180
The information shown here only shows a principal sum, a rate of interest and a period or time. There is no question as to what is needed. But suppose the need is for simple interest, then we calculate using the given information and the formula:
I = PRT
where I is simple interest, P is the principal, R is the rate per year, and T is time
P = 290, T is 6 months which is 0.5 years, R = 12.5 % which is written as 0.125 in decimal fraction.
I = 290 × 0.125 x 0.5 → I = 18.125
Therefore after 6 months , the interest earned will be 18. 125 dollars