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
Answer: 49x^2=-21x-2 quadratic functions -1/7and -2/7
Step-by-step explanation:
Quadratic function:
In elementary algebra, the quadratic formula is a formula that provides the solution to a quadratic equation. There are other ways of solving a quadratic equation instead of using the quadratic formula, such as factoring, completing the square, graphing and others.
Move terms to the left side
49
=-21x-2
49
-(-21x-2) =0
Distribute
49
-(-21x-2) =0
49
+21x+2=0
Use the quadratic formula
x=(-b±√
-4ac ) / 2a
Once in standard form, identify a, b, and c from the original equation and plug them into the quadratic formula.
49
+21x+2=0
let, a=49
b=21
c=2
Replace with values in this equation
X=(-b±√
-4ac ) / 2a
Simplify
Evaluate the exponent
Multiply the numbers
Subtract the numbers
Evaluate the square root
Multiply the numbers
x=(-21±7) /98
Separate the equations
To solve for the unknown variable, separate into two equations: one with a plus and the other with a minus.Separate
x=(-21+7) /98
x=(-21-7) /98
Solve
Rearrange and isolate the variable to find each solution
x=-1/7
x=-2/7
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F(n)=f(n-1)+3 such that
f(1)=2
Answer:
12 months
Step-by-step explanation:
Given that:
Mario:
12 stamps per month
Since January
Karen :
18 stamps per month
Starts on july
Number of stamps collected by Mario till the end of June :
12 * 6 = 72 stamps
For Mario :
72 + 12x
For karen:
18x
Where x is the number of months after karen starts :
Equate both equations
72 + 12x = 18x
72 = 18x - 12x
72 = 6x
x = 72/6
x = 12
After 12 months
Number of months after karen starts, will they have same amount of stamp