Subtract 8d from both sides
21 = 12d + 5 - 8d
Simplify 12d + 5 - 8d to 4d + 5
21 = 4d + 5
Subtract 5 from both sides
21 - 5 = 4d
Simplify 21 - 5 to 16
16 = 4d
Divide both side by 4
16/4 = d
Simplify 16/4 to 4
4 = d
Switch sides
d = 4
<u>Check answer</u>
8d + 21 =12d + 5
Let d = 4
8 × 4 + 21 = 12 × 4 + 5
Simplify 8 × 4 to 32
32 + 21 = 12 × 4 + 5
Simplify 12 × 4 to 48
32 + 21 = 48 + 5
Simplify 32 + 21 to 53
53 = 48 + 5
Simplify 48 + 5 to 53
53 = 53
Ur output value is f(x).....so to do this problem u need to sub in 2/3 for f(x) and solve for the input value which is x
f(x) = -1/3x + 7
2/3 = -1/3x + 7 ...multiply everything by 3
2 = -x + 21
2 - 21 = - x
- 19 = -x
19 = x <== ur output
ANSWER
Three (3) cartons of juice
Y=3X+68.25
80=3X+68.25
Subtract 68.25 from both sides
11.75=3X
Divide
11.75/3=3.91
He can't buy a portion of a juice but he doesn't have enough to buy 4
So he can afford 3 juice cartons
Answer:
44.58
Step-by-step explanation:
I basically pick a couple random numbers for both variables and plug them in to see if they are true.