Answer:
2) x = -2
, y = 2
3) no solution exists
Step-by-step explanation:
Solve the following system:
{-2 x - 3 y = -2
y = 2 x + 6
Hint: | Perform a substitution.
Substitute y = 2 x + 6 into the first equation:
{-2 x - 3 (2 x + 6) = -2
y = 2 x + 6
Hint: | Expand the left hand side of the equation -2 x - 3 (2 x + 6) = -2.
-2 x - 3 (2 x + 6) = (-6 x - 18) - 2 x = -8 x - 18:
{-8 x - 18 = -2
y = 2 x + 6
Hint: | Choose an equation and a variable to solve for.
In the first equation, look to solve for x:
{-8 x - 18 = -2
y = 2 x + 6
Hint: | Isolate terms with x to the left hand side.
Add 18 to both sides:
{-8 x = 16
y = 2 x + 6
Hint: | Solve for x.
Divide both sides by -8:
{x = -2
y = 2 x + 6
Hint: | Perform a back substitution.
Substitute x = -2 into the second equation:
Answer: {x = -2
, y = 2
Answer:
Option C.) 6x=320
Step-by-step explanation:
we know that
The <u>Multiplication Property of Equality</u> states that if you multiply both sides of an equation by the same number, the sides remain equal
we have
Apply the multiplication property of equality
Multiply by 8 both sides
therefore
The answer is the Option C
I know of two ways to solve quadratic equations. The first is through factoring. Let us take the example (x^2)+2x+1=0. We can factor this equation out and the factors would be (x+1)(x+1)=0. To solve for the roots, we equate each factor to 0, that is
x+1=0; x+1=0
In this case, the factors are the same so the root of the equation is
x=1.
The other way is to use the quadratic formula. The quadratic formula is given as [-b(+-)sqrt(b^2-4ac)]/2a where, using our sample equation above, a=1, b=2 and c=1. Substitute these to the formula, and you will get the same answer as the method above.
Answer:
C
Step-by-step explanation:
{(-5,64), (2,1)}
linear equation: y = -9x + 19
quadratic equation: y = x² - 6x + 9
Substitute the y in the quadratic equation by the its value in the linear equation.
-9x + 19 = x² - 6x + 9
- 19 - 19 *subtract 19 to both sides
-9x = x² - 6x -10
+9x + 9x *add 9x to both sides
0 = x² + 3x - 10
0 = (x + 5) (x - 2) *Factor
Set each factor = 0 and solve
x + 5 = 0 ; x - 2 = 0
x = -5 ; x = 2
Find the corresponding value of y using the linear equation.
y = -9x + 19
x = -5 x = 2
y = -9(-5) + 19 y = -9(2) + 19
y = 45 + 19 y = -18 + 19
y = 64 y = 1
(-5,64) (2,1)
Check each value on each equation.
y = x² - 6x + 9
(-5,64) (2,1)
64 = (-5)² - 6(-5) + 9 1 = 2² - 6(2) + 9
64 = 25 + 30 + 9 1 = 4 - 12 + 9
64 = 64 1 = 1
y = -9x + 19
64 = -9(-5) + 19 1 = -9(2) + 19
64 = 45 + 19 1 = -18 + 19
64 = 64 1 = 1
{(-5,64), (2,1)}
