147k views
4 votes
I will give you the brainlessest if you awnser the following plz and thank you so much

2. The sum of two numbers is 82. Their difference is 24. Write a system of equations that describes this situation. Solve by elimination to find the two numbers.

3. Solve the system of equations using substitution.
y = 4x + 6
y = 2x

4.Solve the system using elimination.
5x + 8y = –29
7x – 2y = –67

5. What is the solution of the system of equations?
y = –4x + 6
y = –5x – 4

6.Suppose you are determining the growth rate of two species of plants. Species A is 12 cm tall and grows 2 cm per month. Species B is 10 cm tall and grows 3 cm per month. Which system of equations models the height of each species H(m) as a function of months m.

7. Write the following inequality in slope-intercept form.-8x+4y>-52
_

8.Solve the system using elimination.
3x – y = 28
3x + y = 14

10.Write the following inequality in slope-intercept form.5x-5y>70
_

11.A motorboat can go 8 miles downstream on a river in 20 minutes. It takes 30 minutes for the boat to go upstream the same 8 miles. Find the speed of the current.

12.What is the solution of the system of equations?
y = 4x + 4
y = –3x – 3

13.Write the following inequality in slope-intercept form.-12x-2y>-42
_

14.Find a solution to the following system of equations.
-5x+2y=9
3x+5y=7


15.What is the solution of the system of equations?
3x + 6y = –2
15x + 30y = –10

I will give you the brainlessest if you awnser the following plz and thank you so-example-1
I will give you the brainlessest if you awnser the following plz and thank you so-example-1
I will give you the brainlessest if you awnser the following plz and thank you so-example-2

1 Answer

7 votes
2. x + y = 82
x - y = 24
---------------add
2x = 106
x = 53

x + y = 82
53 + y = 82
y = 82 - 53
y = 29

solution is : (53,29)
=======================
3. y = 2x
y = 4x + 6

2x = 4x + 6
2x - 4x = 6
-2x = 6
x = -3

y = 2x
y = 2(-3)
y = -6

solution is (-3,-6)
========================
4. 5x + 8y = -29
7x - 2y = -67...multiply by 4
----------------
5x + 8y = -29
28x - 8y = - 268 ..result of multiplying by 4
-----------------add
33x = - 297
x = - 9

5x + 8y = -29
5(-9) + 8y = -29
-45 + 8y = -29
8y = -29 + 45
8y = 16
y = 2

solution is : (-9,2)
=======================
5. y = -4x + 6
y = -5x - 4

-4x + 6 = -5x - 4
-4x + 5x = -4 - 6
x = -10

y = -4x + 6
y = -4(-10) + 6
y = 40 + 6
y = 46

solution is (-10,46)
=========================
6. H(m) = 2m + 12
H(m) = 3m + 10
=========================
7. -8x + 4y > -52
4y > 8x - 52
y > 2x - 13 <==
=========================
8. 3x - y = 28
3x + y = 14
---------------add
6x = 42
x = 7

3x - y = 28
3(7) - y = 28
21 - y = 28
-y = 28 - 21
-y = 7
y = -7

solution is (7,-7)
=====================
10. 5x - 5y > 70
-5y > -5x + 70
y < x - 14 <==
=====================
11. sorry...dont know
=====================
12. y = 4x + 4
y = -3x - 3

4x + 4 = -3x - 3
4x + 3x = -3 - 4
7x = -7
x = -1

y = 4x + 4
y = 4(-1) + 4
y = 0

solution is (-1,0)
=======================
13. -12x - 2y > - 42
-2y > 12x - 42
y < -6x + 21 <==
=======================
14. -5x + 2y = 9
3x + 5y = 7

solution is (-1,2)
========================
15. 3x + 6y = -2
15x + 30y = -10....divide by 5 to reduce = 3x + 6y = -2
is the same line....infinite solutions
========================
1. (the graph).....y < = 3x - 4....3rd one
========================
9. (2nd graph)....y < = -3x + 4....last one
User Fatal
by
8.3k points