Answer:
(x, y) = (5, 1)
Step-by-step explanation:
To <em>eliminate</em> x, you can double the second equation and subtract the first.
... 2(x +4y) -(2x -3y) = 2(9) -(7)
...11y = 11 . . . . . simplify
... y = 1 . . . . . . divide by 11
Using the second equation to find x, we have ...
... x + 4·1 = 9
... x = 5 . . . . . subtract 4
_____
<u>Check</u>
2·5 -3·1 = 10 -3 = 7 . . . . agrees with the first equation
(Since we used the second equation to find x, we know it will check.)
Answer:
2×2=4
Step-by-step explanation:
...................
To find the inverse of this function, we first need to replace f(x) with y.
y = 2x^2 + 3
Now, we swap x and y
x = 2y^2 + 3
Now, we solve for y.
-3
x - 3 = 2y^2
Sqrt both sides.
√(x - 3) = 2y
Divide by 2
√(x - 3)/2 = y
Replace y with f^-1(x)
√(x - 3)/2 = f^-1(x)
Just realized you were asking for f(-1), not f^-1(x)
Feels bad.
f(-1) = 2(-1^2 + 3)
f(-1) = 2(-1^5)
f(-1) = 2(-1)
<u>f(-1) = -2</u>
I'm leaving the original answer in case you also need the inverse function. :)
