Answer:
C 40
Step-by-step explanation:
1 blue : 2 white
multiply both sides of the proportion by 20 to reach 20 blue marbles
20 blue: 40 white
1) an = a1 + d*(n-1) => a20 = -4 + (-9)*19 = -4 - 171 = - 175
1) ---> C)
2) a81 = 20 + 4*80 = 340;
2) ---> A)
3) a12 = ?
3) ---> B) or D).
The appropriate choice is ...
... On Line 3, Brianna should have divided by 0.1 instead of subtracting 0.1.
_____
Had Brianna simplified her effort properly on line 4, she would have
... -0.1 +0.1x = -1.4
putting her essentially back where she started—with a 2-step equation.
-1.25 gallon is the change of the amount of water after 1/3 of an hour.
You just need to times -3.75 by 1/3 and you will get the answer of 1/3 hour
