2x+8x=30. x= #of pens
10x=30. combine like terms
x=3. divide by 10 to isolate (get by itself) x
2(3)=6. the # of white pens are represented by 2x
6 white pens
hope this helped!
Answer:
8 and 10
Step-by-step explanation:
Set the first number as x, the second as y
x+y=18
2x-y=6
This is an binary system of first order equations
3x=24
x=8
y=10
Answer:
(x) = √ x + 4
Step-by-step explanation:
step 1) replace f(x) with y
y = x² - 4
step 2) switch the x and y (because every (x, y) has a (y, x))
x = y² - 4
step 3) add 4 to both sides of the equal sign
x + 4 = y²
step 4) take the square root of both sides of the equal sign (the square root symbol cancels out the ²)
√ x + 4 = y
step 5) you know have the inverse of f(x) = x² - 4
(x) = √ x + 4