I hope this helps you
2x^2-4x+7=0 a=2 b=-4 c= 7
disctirminant =b^2-4ac
disctirminant =(-4)^2-4.2.7
disctirminant = 16-56= -40
x=-b+square root of disctirminant ÷2a
x=4+2square root of (-10)/4
x=2+square root of (-10)/2
x'=4 -2 square root of (-10)/4
x'=2 -square root of (-10)/2
You want to eliminate one of the terms (x or y) in one of the equations so you can solve for the other variable. You have to multiply by the opposite number of the coefficient to be able to eliminate the term in the other equation. If the x coefficient is 2, then you have to multiply the entire other equation by -2. If the y coefficient is -5, then you have to multiply the entire other equation by 5.
10)
-4x + 9y= 9
x - 3y= -6
STEP 1:
multiply the bottom equation by 4
4(x- 3y)= 4(-6)
4x - 12y= -24
STEP 2:
add the top equation and the equation from step 2
-4x + 9y= 9
4x - 12y= -24
the x term cancels out
-3y= 15
divide both sides by -3
y= -5
STEP 2:
substitute the y value in either original equation to solve for x
x - 3y= -6
x - 3(-5)= -6
x + 15= -6
subtract 15 from both sides
x= -21
ANSWER: x= -21; y= -5
____________________
12)
-7x + y= -19
-2x + 3y= -19
STEP 1:
multiply the top equation by -3 to eliminate the y term and to solve for x
-3(-7x + y)= -3(-19)
21x - 3y= 57
STEP 2:
add the bottom equation and the equation from step 2 to solve for x
-2x + 3y= -19
21x - 3y= 57
the y term cancels out
19x= 38
divide both sides by 19
x= 2
STEP 3:
substitute the x value in step 2 to solve for y; you can use either original equation
-7x + y= -19
-7(2) + y= -19
-14 + y= -19
add 14 to both sides
y= -5
ANSWER: x= 2; y=-5
Hope this helps! :)
Answer:
x-x-y
Step-by-step explanation:
Answer:
1. No
2. No
3. Yes
4. No
Step-by-step explanation:
The first one isn't proportional because it doesn't start at 0
The second one isn't proportional because there isn't a pattern between the coordinates
The 3rd one is a proportional relationship because it starts at 0 and there is an equal amount of space between each coordinate and there is evidentially a pattern.
Finally, the 4th one isn't proportional because the last coordinate doesn't correspond w/ the others
Plz mark me brainliest if correct :)
Answer:
13:11
Step-by-step explanation:
325:275
If divided by 5 all through, you get 65:55, then by 5 again you get 13:11
