Answer:the length of time he spent running is 8 minutes.
the length of time he spent swimming is 15 minutes.
Step-by-step explanation:
Let x represent the length of time he spent running.
Let y represent the length of time he spent swimming.
He exercised for a total of 23 minutes. This means that
x + y = 23
When running he burns 35 calories per minute, and when he swims he burns 30 calories per minute. He has burned 730 calories after exercising. It means that
35x + 30y = 730 - - - - - - - - - -1
Substituting x = 23 - y into equation 1, it becomes
35(23 - y) + 30y = 730
805 - 35y + 30y = 730
- 35y + 30y = 730 - 805
- 5y = - 75
y = - 75/ -5
y = 15
Substituting y = 15 into x = 23 - y, it becomes
x = 23 - 15 = 8
−4x+18>2x+12
−4x+18−18>2x+12−18
−4x−2x>2x−6−2x
−6x>−6
Multiply both sides by −1 and reverse the inequality
(−6x)(−1)<(−6)(−1)
6x<6
x<1
In interval notation (-∞, 1)
Answer:
450 seconds
Step-by-step explanation:
7.5 x 60= 450
Answer:
f(9) = 72
Step-by-step explanation:
This is a piecewise function. You have to establish what part to plug in your x value based on the designations given in the function. In this case, x=9.
9>6, so we would follow the bottom designation! When writing the function, turn every "x" into a 9.
f(x) = 8x
f(9) = 8(9)
f(9) = 72
Hope this helps you out :)!
