60% of the total (30) can swim
60% of 30 = (60/100)*30 = 0.60*30 = 18
So 18 children can swim
This means 30-18 = 12 cannot swim
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An alternative is to do it this way:
We know 60% can swim so that means 40% cannot swim.
Notice how 100% - 60% = 40%
Or in other words, the 60% and 40% add to 100%. This is because we have two choices: either the person can swim or cannot swim
Since 40% cannot swim, this means
40% of 30 = (40/100)*30 = 0.40*30 = 12
and we get the same result as before
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Final Answer: 12
You know the formula of discriminant
a b
c d
that means ad-bc
So <span>we have an equation
(-12)x3-(2f)x(-w</span>²)= 2k x 3- (-14)x(-81)
0r -36 +2fw²= 6k- 1134
And 2fw²-6k+ 1098=0
But I did not know what is variable here?
Answer:
Required coefficient :coefficient of 1st, 2nd, 3rd and 4th term are 1, 3,3,1 respectively.
Explanation:
Formula for binomial expansion is 
We will substitute the values a=a, b=b and n=3 in the formula for binomial expansion we will get

After simplification of the terms we will get

Since, 
Therefore the required coefficient : coefficients of 1st, 2nd, 3rd and 4th term are 1, 3,3,1 respectively.
Answer:
B
Step-by-step explanation:
Answer:
y = -4x+15
Step-by-step explanation:
y=x/4+5 may be presented as y = 1/4 x + 5, where a=1/4, b=5
swapping numerator and denominator and inserting an opposite sign in a=1/4, we have:
1/4 --------> 4/1 -------> -4/1 = -4
y = -4x+n
Point (2,7) means that x=2, y=7 substitute it to the equation y=-4x+n, calculate "n":
7=-4*2+n ------> 7=-8+n -------> 7+8 = n -------> 15=n
substituting n=15 to the equation y=-4x+n, we get finally y=-4x+15