A biologist studied the populations of white-sided jackrabbits and black-tailed jackrabbits over a 5-year period. The biologist modeled the populations, in thousands, with the following polynomials where x is time,
in years.
White-sided jackrabbits: 9.7x’ - 0.8x + 2.3
Black-tailed jackrabbits: -1.10 + 7.7r + 5.4
What polynomial models the total number of white-sided and black-tailed jackrabbits?
C.
1-8.6r? +6.9x - 7.7
b. 8.6x6.9.r + 7.7
8.6r +6.9x + 7.7
d. 8.6r -6.9.x - 7.7

Will give brainliest what is the value of x? enter your answer in the box.

Two cyclists 84 miles apart start riding toward each other at the samen time. one cycles 2 times as fast as the other. if they meet 4 hours later what is the speed (in miles) of the faster cyclists

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?