I don't know what the "six-step method" is supposed to be, so I'll just demonstrate the typical method for this problem.
Let <em>x</em> be the amount (in gal) of the 50% antifreeze solution that is required. The new solution will then have a total volume of (<em>x</em> + 60) gal.
Each gal of the 50% solution used contributes 0.5 gal of antifreeze. Similarly, each gal of the 30% solution contributes 0.3 gal of antifreeze. So the new solution will contain (0.5 <em>x</em> + 0.3 * 60) gal = (0.5 <em>x</em> + 18) gal of antifreeze.
We want the concentration of antifreeze to be 40% in the new solution, so we need to have
(0.5 <em>x</em> + 18) / (<em>x</em> + 60) = 0.4
Solve for <em>x</em> :
0.5 <em>x</em> + 18 = 0.4 (<em>x</em> + 60)
0.5 <em>x</em> + 18 = 0.4 <em>x</em> + 24
0.5 <em>x</em> - 0.4 <em>x</em> = 24 - 18
0.1 <em>x</em> = 6
<em>x</em> = 6/0.1 = 60 gal
The formula for quadratic equation is given by:
x² - (sum)x + (product) = 0
so if we have real roots of 3 and 5
<span> x² - (3 + 5)x + (3*5) = 0
</span> x² - 8<span>x + 15 = 0
</span>
so if we have real roots of -3 and -6
<span> x² - (-3 - 6)x + (-2*-6) = 0
</span> x² - (-9<span>x) + 12 = 0
</span> x² + 9<span>x + 12 = 0</span>
Answer:
D
Step-by-step explanation:
I just did this test and D was the right answer.
Answer:
the 13th one is 115
Step-by-step explanation:
Answer:
so 4 times 5 is 20 girls
your answer is 20
Step-by-step explanation:
you have to do cross math so 3 over 4 times 5 over? so
