Let <em>x</em> and <em>y</em> be the amounts (in mL) of the 4% and 15% solutions, respectively, that the scientist needs to use.
He wants to end up with a 44 mL solution, so
<em>x</em> + <em>y</em> = 44 mL
Each milliliter of 4% solution contains 0.04 mL of acid, while each mL of 15% contains 0.15 mL of acid. The resulting solution should have a concentration of 12%, so that each mL of it contains 0.12 mL of acid. Then the solution will contain
0.04<em>x</em> + 0.15<em>y</em> = 0.12 × (44 mL) = 5.28 mL
of acid.
Solve for <em>x</em> and <em>y</em>. In the first equation, we have <em>y</em> = 44 mL - <em>x</em>, and substituting into the second equation gives
0.04<em>x</em> + 0.15 (44 mL - <em>x</em>) = 5.28 mL
0.04<em>x</em> + 6.6 mL - 0.15<em>x</em> = 5.28 mL
1.32 mL = 0.19<em>x</em>
<em>x</em> ≈ 6.95 mL
==> <em>y</em> ≈ 37.05 mL
Answer:
A
Step-by-step explanation:
f(x) = x² + 3x + 5
Substitute x value with (a+ h)
f(a+h) = (a+h)² + 3(a+h) + 5
= a² +2ah +h² + 3a + 3h + 5
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Answer:
Modulus of z i.e |z| is ![|z|=\sqrt{218}](https://tex.z-dn.net/?f=%7Cz%7C%3D%5Csqrt%7B218%7D)
Step-by-step explanation:
We are given
and we need to find |z|
|z| is modulus of complex number
The formula used is: ![|z|=\sqrt{a^2+b^2}](https://tex.z-dn.net/?f=%7Cz%7C%3D%5Csqrt%7Ba%5E2%2Bb%5E2%7D)
In the given question
a= 13 and b= -7
Putting values and finding |z|
![|z|=\sqrt{a^2+b^2}\\|z|=\sqrt{(13)^2+(-7)^2}\\|z|=\sqrt{169+49} \\|z|=\sqrt{218}](https://tex.z-dn.net/?f=%7Cz%7C%3D%5Csqrt%7Ba%5E2%2Bb%5E2%7D%5C%5C%7Cz%7C%3D%5Csqrt%7B%2813%29%5E2%2B%28-7%29%5E2%7D%5C%5C%7Cz%7C%3D%5Csqrt%7B169%2B49%7D%20%5C%5C%7Cz%7C%3D%5Csqrt%7B218%7D)
So, Modulus of z i.e |z| is ![|z|=\sqrt{218}](https://tex.z-dn.net/?f=%7Cz%7C%3D%5Csqrt%7B218%7D)
Answer:
Step-by-step explanation:
167:1000=0,167 dekameters