Question

Help with both please & with explanation :)

Answer 1

5. (0, -4) ; 6. (8, 6)

Explanation:

5. Using elimination, we must distribute a value that will make the x and/or y value opposite (but the same) to one another. In this case we could distribute -3 to the top equation to get an opposite value (to the bottom) of -3x. This changes the top equation to -3x - 21y = 84. When we add the systems of equations together we get -26y = 104. The y simplifies to -4. Then we have to use the substitution method to find the x value. We substitute the y for -4 in the bottom equation to get 3x + 20 = 20. When we simplify we get x = 0. So the answer is (0, -4).

6. Using elimination, we must again distribute a value to make the equation opposite but equal to make at least one of the variables opposite but equal to each other. In this case, the least common denominator between 2x and 9x (x because it is less than the y value) is 18. We can multiply the top equation by -9 and we distribute it. To make both equal (and opposite) we also have to multiply the bottom equation by 2. The simplified equation is -18x + 27y = 18. Adding the system of equations together gets us 7y = 42, or y = 6. Once again use substitution (on either equation) and you get an x value of 8. The answer is (8, 6).

Answer 2

5)x=0,y=-4

6)x=8&y=6

Explanation:

5)x+7y=-28

3x-5y=20

x=0, y=-4

for x+7y=-28 let's get "x" by itself, so bring 7y to the right

x=-28-7y

now that we have the value of "x"let's substitute it in "3x-5y=20"

3(−7y−28)−5y=20

-21y-84-5y=20

−26y−84=20(Simplify both sides of the equation)

−26y−84+84=20+84(Add 84 to both sides)

−26y=104

−26y /-26=104/-26

(Divide both sides by -26)

y=−4

Step: Substitute−4 for y in "x=−7y−28:"

x=−7y−28

x=(−7)(−4)−28

x=0(Simplify both sides of the equation)

Answer:

x=0 and y=−4

USE THIS METHOD FOR #6 as well hope this helps!