HELP PLEAS ITS DUE SOON! SHOW YOUR WORK & ILL GIVE BRAINLIEST I PROMISE question: solve the system of equation using substitution.

5x-2y=-10
3x+6y=66

1

(2,10) or x=2 y=10

Step-by-step explanation:

1. Pick one of your equations and solve for a variable. I chose the first equation and solved for x.

5x-2y=-10 (Move the -2y to the other side, you need to do the opposite so you add +2y to -10)

5x=2y-10 (Divide the 5 from the x)

x=2/5y-2

2. Now take what you got for x and plug it into the x variable on the other equation.

3(2/5y-2)+6y=66 (Multiply 3 by 2/5y and -2)

6/5y-6=6y=66 (Move the -6 to the other side and add 6/5y to 6y)

36/5y=72 (Since the number on the y is a fraction, you must do the opposite to the other side)

y=72/1 x 5/36 (Flip your fraction and multiply it by the 72)

y=10

3. Now that you have one of the variables solved for, in order to get the other we must plug in what we have to the first equation.

5x-2(10)=-10 (Multiple 2 by 10)

5x-20=-10 (Move -20 to the other side, since you do the opposite add +20 to the -10)

5x=10 ( Divide 10 by 5)

x= 2

4. If needed, plug in the values of x and y to check your solution.

Hope this could help! :)

part a

answer: a reasonable domain is where n is a real number. so n can be between 0 and 10. both endpoints are included.

work shown:

n is the number of days after the experiment starts. the smallest n can be is n = 0 which means that 0 days have gone by, and we're at the start. to find out how large n should be, then replace f(n) with 16.13 and solve for n. use logarithms to isolate the exponent.

f(n) = 12*(1.03)^n

16.13 = 12*(1.03)^n

16.13/12 = (1.03)^n

1.34416666666667 = (1.03)^n

(1.03)^n = 1.34416666666667

log[ (1.03)^n ] = log[ 1.34416666666667 ]

n*log[ 1.03 ] = log[ 1.34416666666667 ]

n = log[ 1.34416666666667 ]/log[ 1.03 ]

n = 10.0062999823929

this rounds to n = 10 which is fairly close but not 100% perfect. so this is the largest n can be.

note: if you plug n = 10 into f(n), you'll get roughly 16.127 which rounds to 16.13 (this comes up again in part c)

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part b

answer: the y intercept is 12. it represents the starting height of the plant in cm.

work shown:

plug n = 0 into the f(n) function. simplify

f(n) = 12*(1.03)^n

f(0) = 12*(1.03)^0

f(0) = 12*(1)

f(0) = 12

on day n = 0, aka the starting point, the height f(n) is 12 cm

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part c

answer: the average rate of change is approximately 0.43061036458991 (round however you need to). this represents the average growth rate from day n = 3 to day n = 10. so the plant grew roughly 0.43 cm per day during this timespan, assuming you round to 2 decimal places.

work shown:

compute f(3)

f(n) = 12*(1.03)^n

f(3) = 12*(1.03)^3

f(3) = 13.112724 < we'll use this later

compute f(10)

f(n) = 12*(1.03)^n

f(10) = 12*(1.03)^10

f(10) = 16.1269965521294 < we'll use this later

now use the formula below with a = 3 and b = 10

aroc = average rate of change

aroc = [ f(b) - f(a) ]/[ b - a ]

aroc = [ f(10) - f(3) ]/[ 10 - 3 ]

aroc = (16.1269965521294 - 13.112724)/(10 - 3)

aroc = 3.0142725521294/7

aroc = 0.43061036458991

round this however you need to

note: the plant grew approximately 3.01 cm over 7 days, so roughly 0.43 cm per day is the average growth rate (if you were to round to 2 decimal places).

solve systems of equations by graphing. a system of linear equations contains two or more equations e.g. y=0.5x+2 and y=x-2. the solution of such a system is the ordered pair that is a solution to both equations. to solve a system of linear equations graphically we graph both equations in the same coordinate system