Answer:
L=10cm , W=30cm
Step-by-step explanation:
First use the given that W=10+2*L
Use P=2W+2L=80, substitute W in the perimeter formula
2(10+2L)+2L=80 and solve for L,
20+4L+2L=80 isolate variable L and combine like terms,
6L=80-20,
L=10, so W=10+2*10=10+20=30
X+10+10=8+10 is not equal to x=18. It must be x+20=18 x=-2
Answer:
C. Both f(x) and its inverse function intersect at point (2, 2).
Step-by-step explanation:
First of all, let's begin defining f(x) = y.
Since the linear function f(x) intersects at
• 6 on the y-axis; and
• 3 on the x-axis;
we can deduce the following equation:
6x + 3y = 6(3)
6x + 3y = 18
3y = -6x + 18
y = -6x/3 + 18/3
y = -2x + 6
f(x) = -2x + 6
Then, we'd want to find the inverse of f(x), which is f`¹(x).
f(x) = -2x + 6
y = -2x + 6
Interchange the variable y to x and vice versa.
x = -2y + 6
2y = -x + 6
y = (-1/2)x + 3
f`¹(x) = (-1/2)x + 3
Since both f(x) and its inverse function are equal to y, set them both as equal.
f(x) = f`¹(x)
-2x + 6 = (-1/2)x + 3
-2x + (1/2)x = 3 - 6
(-3/2)x = -3
x = 2
Substitute x = 2 into y = -2x + 6.
y = -2(2) + 6
y = -4 + 6
y = 2
Now that we know x = 2 and y = 2, then the intersection point of (x, y) must be (2, 2).
I hope this helps! Sorry if my English didn't really help with giving a clearer explanation.
