X = 1 y = 9, x = 5 y = 33, x = 7 y = 45, x = 8 y= 51
Answer:
(5,3)
Step-by-step explanation:
I know this one
So the best way to do these is concentration1 (%) × volume1 = concentration2 × volume2
Or C1V1 + C2V2 = C3V3, where C1 = 100% (bc ALL pecans), V1 = 6 lbs, C2 = 70%, C3 = 82%:
100%×6 + 70%×v2 = 82%×(6+v2)
100%=1.00, 70%=.7, 82%=.82
note: if none is poured out then v3 = v1+v2
6 + .7v2 = .82 (6+v2)
6 + .7v2 = 4.92 + .82v2
6 + .7v2 -.7v2 = 4.92 + .82v2 -.7v2
6 = 4.92 + .12v2
6-4.92 = 4.92-4.92 + .12v2
1.08 = .12v2
.12v2/.12 = 1.08/.12
v2 = 9 lbs
that's only v2!!!
For the final poundage, we need v3:
v3 = 6 + v2 = 6 + 9 = 15 lbs
Let x represent Holly's score on 7th math quiz.
We have been given that the mean of Holly's first six math quiz scores was 75%. This means that the average on 1st 6 math quizzes is 75.
To find the total scores on 1st 6 math quizzes, we will multiply 75 by 6 that is .
We will use average formula to find test scores on 7th math quiz.
Let us solve for x.
Therefore, Molly's score on the 7th math quiz was 89.