Answer:
2/3
Step-by-step explanation:
Let's define z = x-y, so solving for z will tell us exactly what we want to know. Then we can substitute for x: x = z+y, and our equations become ...
7(z+y)+3y = 8 ⇒ 7z +10y = 8
6(z+y)-3y = 5 ⇒ 6z +3y = 5
We can eliminate the y-variable by subtracting 3 times the first equation from 10 times the second:
10(6z +3y) -3(7z +10y) = 10(5) -3(8)
60z +30y -21z -30y = 50 -24 . . . . eliminate parentheses
39z = 26 . . . . collect terms
z = 26/39 = 2/3 . . . . . divide by the coefficient of z and reduce
The value of x - y is 2/3.
_____
The attached graph shows (x, y) = (1, 1/3), so x - y = 1 - 1/3 = 2/3.
Answer:
A.
Step-by-step explanation:
The answer would be a because if you have s + 11 you will get 23
but if you were to find s it would be 12
Answer:
She needs at least 73%
Step-by-step explanation:
1. add all of the numbers up and d the quantity to find
93+67+82+71+94/5
=407/5
=81.
2. try diffrent numbers
407+73/6
=480/6
=80
She needs at least 73%
Answer: C. 180 times
Step-by-step explanation:
From the 60 trials, the percentage of times Laura picked a green marble was:
= 100% - Percentage of times blue and red were picked
= 100% - 25% - 15%
= 60%
If these results were repeated with 300 trials, the number of times Laura would be expected to pick green would be:
= 60% * 300
= 180 times