Answer:
150 mL
Step-by-step explanation:
Let x represent the quantity of 75% solution needed. The total amount of alcohol in the 60% mixture will be ...
75%·x + 10%·45 = 60%·(x+45) . . . . . there will be x+45 mL of solution in the end
0.15x = 22.5 . . . . . . . . . . . . . . . . . . . . simplify, subtract .60x+4.5
22.5/0.15 = x = 150 . . . . . . . . . . . . . . mL of 75% solution needed
You will need 150 mL of the 75% solution.
Sent a picture of the solution to the problem (s).
Answer:
(7/8 - 4/5)^2 = 9/
1600
= 0.005625
Step-by-step explanation:
Subtract: 7/
8
- 4/
5
= 7 · 5/
8 · 5
- 4 · 8/
5 · 8
= 35/
40
- 32/
40
= 35 - 32/
40
= 3/
40
For adding, subtracting, and comparing fractions, it is suitable to adjust both fractions to a common (equal, identical) denominator. The common denominator you can calculate as the least common multiple of both denominators - LCM(8, 5) = 40. In practice, it is enough to find the common denominator (not necessarily the lowest) by multiplying the denominators: 8 × 5 = 40. In the next intermediate step, the fraction result cannot be further simplified by canceling.
In words - seven eighths minus four-fifths = three fortieths.
Exponentiation: the result of step No. 1 ^ 2 = 3/
40
^ 2 = 32/
402
= 9/
1600
In words - three-fortieths squared = nine one-thousand six-hundredths.
