Answer:
I think this is the correct solution
We know that
if <span>4 electricians can complete a job in 8 hours
then
</span>100% of a job -------> 8 hours
x------------------> 1 hour
x=100/8----> x=12.5%
divide by 4 electricians
12.5%/4-----> 3.125%
that means each electrician can complete 3.125% of a job in 1 hour
therefore
3 electricians-----> 3*3.125%----> 9.375% in 1 hour
so
9.375%-----------> 1 hour
100%--------------> x
x=100/9.375----> x=10.67 hours
the answer is
10.67 hours
1) We can determine by the table of values whether a function is a quadratic one by considering this example:
x | y 1st difference 2nd difference
0 0 3 -0 = 3 7-3 = 4
1 3 10 -3 = 7 11 -7 = 4
2 10 21 -10 =11 15 -11 = 4
3 21 36-21 = 15 19-5 = 4
4 36 55-36= 19
5 55
2) Let's subtract the values of y this way:
3 -0 = 3
10 -3 = 7
21 -10 = 11
36 -21 = 15
55 -36 = 19
Now let's subtract the differences we've just found:
7 -3 = 4
11-7 = 4
15-11 = 4
19-15 = 4
So, if the "second difference" is constant (same result) then it means we have a quadratic function just by analyzing the table.
3) Hence, we can determine if this is a quadratic relation calculating the second difference of the y-values if the second difference yields the same value. The graph must be a parabola and the highest coefficient must be 2
You can cross out c and d I think its B but im not positive
Answer:
= -9
Step-by-step explanation:
"increased by" means addition
-21 + 12 or 12-21
= -9
