What is the answer of (3.42 x 10-7) ÷ (7.5 x 10-6) in standard form
1 answer:
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Answer:
A. 26 ft
Step-by-step explanation:
You might recognize that this triangle is a 5-12-13 triangle scaled up by a factor of 2. If so, you know immediately, that the hypotenuse is 2×13 = 26 feet in length.
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If you're not so lucky, you can write equations involving the lengths of the legs of the triangle. Let those be x and y, with x being the shorter leg. Then the Pythagorean relation tells you ...
x² + y² = (x+16)²
and the area relation tells you ...
120 = (1/2)xy
Using the second equation to write an expression for y, we have ...
y = 240/x
Substituting this into the first equation gives ...
x² + (240/x)² = (x+16)²
(240/x)² = 32x +256 . . . . subtract x²
1800 = x²(x +8) . . . . . . . . .multiply by x²/32
This is a cubic with one real root. It can be solved several ways. I like "graphing" as it is quick and easy. Trial and error also works. The factors of 1800 include 10²·18, so it is clear that x=10 is the solution.
The hypotenuse length is x+16, so is 26 feet.
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The attachment shows the graphical solution of the original two equations. This tells you the legs of the triangle are 10 and 24, so the hypotenuse will be 10+16 = 26. The 10-24-26 triangle is recognizable as a scaled version of the 5-12-13 triangle often used in math problems.
m = 90 - 6d is the equation to determine m, the number of measures Harita still needs to memorize, as a function of d, the number of days of practice since she began learning the piece
<em><u>Solution:</u></em>
Given that Harita must memorize 90 measures of music for her cello solo at a concert
To find: equation to determine m, the number of measures Harita still needs to memorize, as a function of d, the number of days of practice since she began learning the piece
Let "m" be the number of measures Harita still needs to memorize
Let "d" be the number of days of practice since she began learning the piece
Given that She plans on memorizing 18 new measures for every 3 days of practice
<em><u>Rate per day is given as:</u></em>
Therefore she memorises 6 per day
<em><u>Therefore, the equation that relates 'm' to 'd' is: </u></em>
m = total measures of music she must memorise - (number of measures she memorises per day x d)
m = 90 - 6(d)
m = 90 - 6d
Thus the required equation is found