You would multiply 4 by 72 then u multiply 4 * -6 then after that you would add 15
Due to the order of operations the correct answer is 6+2*5=16
Answer:
Step-by-step explanation:
R = 9x + 8y
4 = 9x + 8*8
4 = 9x + 64
Subtract 64 from both sides
4 - 64 = 9x + 64 - 64
-60 = 9x
Divide both sides by 9
-60/9 = 9x/9
-20/3 = x
x = -6 2/3
Change x+y=5 to y=5-x
x+5-x=-3
0=-8
The answer is no solution. :)
Answer:
- 6 2/3 qt 80%
- 13 1/3 qt 20%
Step-by-step explanation:
It is often convenient to solve a mixture problem by letting a variable represent the quantity of the higher-concentration contributor to the mix.
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We can let x represent the number of quarts of 80% solution needed. Then (20-x) is the number of quarts of 20% solution needed. The amount of salt in the final mix is ...
0.80x +0.20(20-x) = 0.40(20)
0.60x = 0.20(20) . . . . . . . . subtract 0.20(20) and simplify
x = 20/3 = 6 2/3 . . . . . . . . . divide by 0.60; quarts of 80% solution
(20 -x) = 13 1/3 . . . . . . . . . . amount of 20% solution needed
The teacher should mix 6 2/3 quarts of 80% solution with 13 1/3 quarts of 20% solution.
