Simplify the expression 11x + 9 - 7 =
1 answer:
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Answer:
4/9
Step-by-step explanation:
Let the amount of 95% sol = a ml and
the amount of 30% sol = b ml.
So, the total amount of the compound=a+b=500 ml
As the compound is 50% solution, so
95% of a + 30% of b= 50% of (a+b)
(95/100)a+(30/100)b=(50/100)(a+b) [from equation (i)]
95a + 30b = 50(a+b)
95(a/b)+30 = 50(a+b)/b [dividing both sides by b]
95(a/b)+30 = 50(a/b+1)
95(a/b)+30 = 50(a/b)+50
95(a/b)-50(a/b)=50-30
45(a/b)=20
a/b=20/45
a/b=4/9
Therefore, a:b=4:9
As a+b= 500 ml, so the amount of 95% sol = ml
and the amount of 95% sol = ml
Hence, the proportion of 95% sol and 30% sol to make a compound of 50% sol must be 4/9.
The answer is 6x+5y-9=0.
The procedure is above.
Answer:
x = 25
Step-by-step explanation:
Using Pythagoras' identity in the right triangle.
The square on the hypotenuse x is equal to the sum of the squares on the other two sides, that is
x² = 20² + 15² = 400 + 225 = 625 ( take the square root of both sides )
x = = 25