Let x = your number.
x^2 - 21 = 4x. Subtract 4x from both sides.
x^2 - 4x - 21 = 0. Factor.
(x - 7) (x + 3) = 0. Set each term to 0.
x + 3 = 0. Subtract 3 from both sides.
x = -3. This is the negative solution.
Set the other term equal to zero.
x - 7 = 0. Add 7 to each side.
x = 7. This is the positive solution.
Answer:
5:1
Step-by-step explanation:
Answer: (x,y) = (-1, 1)
This means that x = -1 and y = 1
========================================================
Explanation:
The first equation says that y is the same as 2x+3
That allows us to substitute y for 2x+3 in the second equation like so:
2x+5y = 3
2x+5( y ) = 3
2x + 5(2x+3) = 3 .... y replaced with 2x+3
2x+10x+15 = 3
12x+15 = 3
12x = 3-15
12x = -12
x = -12/12
x = -1
Then we'll substitute this into the first equation to find y
y = 2x+3
y = 2(-1) + 3 .... x replaced with -1
y = -2+3
y = 1
Together x = -1 and y = 1 pair up to form the ordered pair solution (x,y) = (-1,1)
If you were to graph y = 2x+3 and 2x+5y=3 on the same xy grid, then you should see that the two lines intersect at the location (-1,1). This is a visual way to determine the solution quickly through use of a graphing calculator.
Answer:
the answer should be always, which would be b
Step-by-step explanation:
if you have a reciprocal 3/2 then the fraction would be 2/3 which is proper. you just flip the numbers.