13 1/3 because 40 divided 3 is 13 ….
f(x)=2x+5
first find inverse
write it without f(x)
y = 2x + 5
x = 2y + 5 swap the variables, now solve for y
- 5 -5
x - 5 = 2y
/2 /2 divide both sides by 2
(x-5)/2 = y
so f-1(x) = (x-5)/2
f-1(8) = (8-5)/2
= (3)/2
f-1(8) = 3/2
Answer:
360 = x + 30
x = 390 meters
Step-by-step explanation:
X + y = 2
Substitute x + 8 into y
x + x + 8 = 2
2x + 8 =2
(Subtract 8 from both sides)
2x = -6
(Divide both sides by 2)
x = -3
Subsitute x = -3 into either equation to find y
x + y = 2
-3 + y = 2
(Add 3 to both sides)
y = 2 + 3
y = 5
Or y can be solved for using:
y = x + 8
y = -3 + 8
y = 5
C is also the best answer
