Answer:
the value of x is 7.
Step-by-step explanation:
2+19=21
21÷3=7
Check:
3×7=21
21-2=19
Therefore, 7 is the answer.
F(4) is equivalent to 28 because when you plug in 4 for the x, you get 28.
-x - y = 8
2x - y = -1
Ok, we are going to solve this in 2 parts. First we have to solve for one of the variables in one of the equation in terms of the other variable. I like to take the easiest equation first and try to avoid fractions, so let's use the first equation and solve for x.
-x - y = 8 add y to each side
-x = 8 + y divide by -1
x = -8 - y
So now we have a value for x in terms of y that we can use to substitute into the other equation. In the other equation we are going to put -8 - y in place of the x.
2x - y = -1
2(-8 - y) - y = -1 multiply the 2 through the parentheses
-16 - 2y - y = -1 combine like terms
-16 - 3y = -1 add 16 to both sides
-3y = 15 divide each side by -3
y = -5
Now we have a value for y. We need to plug it into either of the original equations then solve for x. I usually choose the most simple equation.
-x - y = 8
-x - (-5) = 8 multiply -1 through the parentheses
-x + 5 = 8 subtract 5 from each side
-x = 3 divide each side by -1
x = -3
So our solution set is
(-3, -5)
That is the point on the grid where the 2 equations are equal, so that is the place where they intersect.
Equations are steeper when their slope's positive value is higher (ignore negatives when determining how steep a slope is). The slope is the value in front of x. If there isn't a value in front of x, then it is assumed to be 1.
Given:
The function is:
To find:
The inverse of the given function, then draw the graphs of function and its inverse.
Solution:
We have,
Step 1: Substitute 
.
Step 2: Interchange x and y.
Step 3: Isolate variable y.
Step 4: Substitute 
.
Therefore, the inverse of the given function is 
and the graphs of these functions are shown below.
