X - 2y = 3
<span>4x^2 - 5xy + 6y = 3
lets solve for x the first and substitute in the second:
x = 3 + 2y
4(</span>3 + 2y)^2 - 5(3 + 2y)y + 6y = 3
4(9 + 12y + 4y^2) - 15y - 10y^2 = 3
36 + 48y +16y^2<span> - 15y - </span><span>10y^2 = 3
6y^2 + 33y + 33 = 0
we can solve using the general quadratic formula:
y = (-33 +- </span>√(33^2 - 4*6*33)<span>)/12
</span>y = (-33 +- √(297)<span>)/12
</span>so there are 2 solutions for y:
y1 = (-33 + √(297)<span>)/12
</span>y2 = (-33 - √(297)<span>)/12
</span>pick one and then substitute the y value in the first equation to find x
Answer:
x = - 2, x = 7
Step-by-step explanation:
Given
f(x) = 4x² - 20x - 56
To find the zeros let f(x) = 0, that is
4x² - 20x - 56 = 0 ( divide through by 4 )
x² - 5x - 14 = 0 ← in standard form
(x - 7)(x + 2) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 2 = 0 ⇒ x = - 2
x - 7 = 0 ⇒ x = 7
Divide the restocking fee by the price of the item:
12/200 = 0.06
9/150 = 0.06
Multiply by 100 to get the percent:
0.06 x 100 = 6%
Answer: 6%
ANSWER
EXPLANATION
Recall that,
That is why
is equivalent to
This implies that,
This is the same as,
When we are dividing by
we move the decimal point backwards two times.
This implies that,
-- 30 miles per hour
-- $6.50 per hour
-- 365 days per year
-- 60 seconds per minute
-- $2.49 per pound
-- 3.47⁹ per gallon
-- 1800 calories per day
-- 360 degrees per revolution
