{2x + y = -1}
{3x- 5y + -21}

your question is not complete or should I say not correct ☺️

(-2, 3).

Step-by-step explanation:

2x + y = -1

3x- 5y = -21

Multiply the first equation by 5:

10x + 5y = -5     Adding this to the second equation:

13x = -26

x = -2.

Substituting this into equation 1:

2(-2) + y = -1

y = -1 + 4 = 3.

Checking this result in the second equation:

3(-2) - 5(3)

= -5 - 15 = -21

- Checks OK.

4a. is 3 miles every hour

4b. is 1/3 of an hour per mile

step-by-step explanation:

the given growth  function for the length of the fish (cm) is

f(m) = 5(1.07)m = 5.35m

where 

m = months

at the end of the study, the length is 9.19 cm. the  time for conducting the study is determined as

5.35m = 9.19

m = 1.7178 months

part a.

the study was performed over a time period  of about 1.72 months. therefore  the domain for  plotting the function is 0 < = m < = 1.72.

note:

if growth  continues at this rate for up to m months, then the domain would be 0< =m< =m.

part b.

the growth function is a linear function.

when m=0, f=0.

therefore the initial growth is zero, which represents the y-intercept.

part c.

assume that the growth function is valid for 0< =m< =9.

the average rate of change of the function is the slope of the linear function, which is 5.35 cm/month.