Answer:
<h2><u><em>
15</em></u></h2>
Step-by-step explanation:
what is the value of 10×+z=150
10× (+z) = 150
10 × z = 150
z = 150 : 10
z = 15
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check
10 × 15 = 150
the answer is good
First I would change the descriptions of the numbers into expressions.
first number is n
second number is n + 6
third number is 4n (4 x n)
Then you would insert these expressions into an equation and isolate n.
n + n + 6 + 4n = 144
n + n + 4n = 144 - 6
6n = 138
n = 138/6
n = 23
Lastly, you would plug in this value into all of the expressions.
first number is 23
second number is 23 + 6 = 29
third number is 4(23) = 92
Therefore, the numbers are 23, 29, and 92.
The easiest way is to try the point (-4,1), that is, x=-4, y=1,
to see which equation works.
b works.
The usual way to do it is to find the equation of the circle
standard form of a circle is (x-h)²+(y-k)²=r², (h,k) are the coordinates of the center, r is the radius.
in this case, the center is (-2,1), so (x+2)²+(y-1)²=r²
the given point (-4,1) is for you to find r: (-4+2)²+(1-1)²=r², r=2
so the equation is (x+2)²+(y-1)²=2²
expand it: x²+4x+4+y²-2y+1=4
x²+y²+4x-2y+1=0, which is answer b.
B(5 - 2, -6 + 3, -1 + 1) = B(3, -3, 0)
Suppose x grams of 8% solution should be mixed to make 100 g of 3% solution.
here we shall have:
the amount of 3% solution in the 100 g will be:
3/100*100=3 grams
the the equation will be, 8% of what quantity becomes 3g?
(8/100)*x=3
hence solving for x we shall have:
0.08x=3
x=3/0.08
x= 37.8 grams
The implication of this is that, when you have 37.5 grams of 8% solution, that will contain 3 of pure chemical and hence when you add more solvent on top of 37.5 g until you reach 100g, that will be 3% solution.
