First set up your two equations:
x + y = 90
x = 2y - 30
Then substitute what x equals in the second equation into the first equation:
(2y -30) + y = 90
Now solve for y:
3y -30 = 90
3y = 120
y = 40
Then use y = 40 and substitute the value for y into one of your original equations and solve for x. I'll choose the first one, but either one will work.
x+ 40 = 90
x = 50
So your solution is x = 50 and y = 40

x = 2
<em>right</em><em> </em><em>option</em><em> </em><em>is</em><em> </em>(E).
Step-by-step explanation:
f(x) = x³ - 3x² + 12 in interval [-2, 4]
{taking f'(x) by doing derivative of f(x)}
f'(x) = 3x² - 6x
.•. f'(x) = 0
0 = 3x² - 6x
0 = 3x(x - 2)
0 = x - 2
x = 2
I guess positive bcuz - -=+
Answer:
2 hours
Step-by-step explanation:
4 square yards to feet: 4*3 = 12ft
3 cows grazing grass at 2 ft per hour: 2*2 = 6 square ft per hour
Time taken: 12ft/6ft per hour = 2 hours