4(x+7)=8x-20
4x+28=8x-20
28=4x-20
48=4x
x=12
Answer:
y= −1 + x/3
Step-by-step explanation:
Isolate the variable by dividing each side by factors that don't contain the variable.
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! :)
<span>Simplifying
2x + n = 3
Reorder the terms:
n + 2x = 3
Solving
n + 2x = 3
Solving for variable 'n'.
Move all terms containing n to the left, all other terms to the right.
Add '-2x' to each side of the equation.
n + 2x + -2x = 3 + -2x
Combine like terms: 2x + -2x = 0
n + 0 = 3 + -2x
n = 3 + -2x
Simplifying
n = 3 + -2x</span>
Answer:
Option C (Negative)
Step-by-step explanation:
A line with a negative slope goes downward from the left side of the graph to the right side.
A positive line would be the opposite; the line goes upward form left to right.
A horizontal line has zero slope. A vertical line has undefined slope.
The given line has the line going downward.
Option C should be the correct answer.
Hope this helps.
