Answer:
unsolvable because the second equation is just -2.5 times the first equation.
Step-by-step explanation:
2x-6y=12 then 2x=12+6y x=6+3y
-5x+15y=-30
substitute x
-5(6+3y)+15y=-30
-30-15y+15y=-30
y=y
Ratio given 1:2
Let's suppose the ratio as x : 2x
Adding the ratio = 3x
40 and 80 are in the ratio 1:2 of 120.
Hope it helps!!!
Answer:
[-5, 2]
Step-by-step explanation:
We have to find the interval for which f(x) <= 0, the interval is [-5, 2].
Take how much was added, divide by how much you originally had. 100-80=20. 20/80= 25%
X² <span>+ 11x + 7
because 7 is a prime number, this doesn't factor prettily. you'll want to use the quadratic formula; if you aren't familiar with it, i'd either research it or look it up in your textbook, because it's clunky and not easily understood in this format:
(-b </span>± √((b)² - 4ac))/(2a)
in your equation x² + 11x + 7 ... a = 1, b = 11, and c = 7. what you do is you take the coefficients of every term, then plug it into your equation:
(-11 ± √((11)² - 4(1)(7))/(2(1))
not pretty, i know. but, regardless, you can simplify it:
(-11 ± √((11)² - 4(1)(7))/(2(1))
(-11 ± √(121 - 28))/2
(-11 ± √93)/2
and you can't simplify it further. -11 isn't divisible by 2, and 93 doesn't have a perfect square that you can take out from beneath the radical. the ± plus/minus symbol indicates that you have 2 answers, so you can write them out separately:
(x - (-11 - √93)/2) and (x + (-11 - √93)/2)
they look confusing, but those are your two factors. they can be simplified just slightly by changing the signs in the middle due to the -11:
(x + (11 + √93)/2) (x - (11 - √93)/2)
and how these would read, just in case the formatting is too confusing for you: x plus the fraction 11 + root 93 divided by 2. the 11s and root 93s are your numerator, 2s are your denominator.
