The first one.............
Answer: x = ¹/₂ ± √⁸¹
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2
Step-by-step explanation:
First write out the equation
x² - x - 20
Now we now write the equation by equating to 0
x² - x - 20 = 0
We now move 20 to the other side of the equation. So
x² - x = 20,
We now add to both side of the equation square of the half the coefficient of the (x) and not (x²) which is (1) . So, the equation now becomes
x² - x + ( ¹/₂ )² = 20 + ( ¹/₂ )²
x² - ( ¹/₂ )² = 20 + ¹/₄
( x - ¹/₂ )² = 20 + ¹/₄, we now resolve the right hand side expression into fraction
( x - ¹/₂ )² = ⁸¹/₄ when the LCM is made 4
Taking the square root of both side to remove the square,we now have
x - ¹/₂ = √⁸¹/₄
x - ¹/₂ = √⁸¹/₂
Therefore,
x = ¹/₂ ± √⁸¹
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2
If f(x) = 2x - 5 and g(x) = x + 52, then f(g(x)) can be deduced by placing g(x) in the spot of x in the f(x) equation as follows:
f(g(x)) = 2(g(x)) - 5
Since we know g(x) = x + 52, let's plug it in:
f(g(x)) = 2(x + 52) - 5
f(g(x)) = 2x + 104 - 5
f(g(x)) = 2x + 99
I think it would be easy to find it because its 30 feet away and even if he didn't know his feet he could always leave rocks/pebbles to the treasure so he won't lose it.
Okay. So Daniella wants to have a take-home pay of at least $51,000, but she ahs to pay 15% income tax, which means 15% of what she earns will be gone. To find out the least amont of salary she needs to make, we can write and solve a proportion. Set it up like this:
51,000/x = 85/100
This is because we are looking for the amount of money made overall, but the $51,000 is only part of the salary earned, and even though you pay 15% income tax, you still take home 85% of your salary. Cross multiply the valyes in order to get 5,100,000 = 85x. Divide each side by 85 to isolate the variable. 5,100,000/85 is 60,000. Let's check this by multiplying by 85% (0.85). 60,000 * 0.85 is 51,000. There. x = 60,000. Daniella will need to make at least $60,000.
