Answer:
To determine what is the difference between "6 + A" and "6 x A", the logic of the proposed mathematical operations must be explained:
In "6 + A", the value A is added to the initial value 6. Thus, for example, if A were worth 10, to the initial value 6 10 units are added, with which the final value is 16.
In contrast, in "6 x A", the initial value 6 is multiplied by as many times as the value A indicates. Therefore, continuing with the value of A as 10, in this case 6 would be multiplied by 10 times, giving a final value of 60.
Let x represent the number of liters of 50% acid Theresa puts into the mix. The the number of liters of 30% acid will be (420-x). The total amount of acid in the final solution will be ...
0.50x + 0.30(420-x) = 0.45(420)
0.20x + 126 = 189 . . . . . . . . . . . . . . . simplify
0.20x = 63 . . . . . . . . . . . . . . . . . . . . . subtract 126
x = 63/0.20 = 315 . . . . . . . . . . . . . . . liters of 50% solution
(420-x) = 420-315 = 105 . . . . . . . . . liters of 30% solution
Theresa should mix ...
105 liters of 30% solution
315 liters of 50% solution
5x^2-3x^2= 2x^2
2x^2-14
2(x^2-7)
Answer:
$0.48
Step-by-step explanation:
$2.40 divided by 5 pounds equals $0.48 per pound.
