Step-by-step explanation:
step 1. 17/21 - 2/10 = x (in order to subtract you need a common denominator)
step 2. (17/21)(10/10) - (2/10)(21/21) = x
step 3. 170/210 - 42/210 = x
step 4. 128/210 = 64/105 = x
step 5. x = 64/105.
Use order of operations for this
4x+17=23
Move the 17 to the 23
4x=23-17
Then move the 4 over leaving the x by itself
X=6/4
X=1.5
Answer:
2x + 1.5y = 15
Step-by-step explanation:
2x + 1.5y = 15 because just plug in the variables.
For this case we have the following system of equations:

From the first equation we clear "x":

We substitute in the second equation:

We apply distributive property:

We add similar terms:

We add 65 to both sides:

We divide between 22 on both sides:

We look for the value of the variable "x":

Thus, the solution of the system is:

ANswer:

To find the specification limit such that only 0.5% of the bulbs will not exceed this limit we proceed as follows;
From the z-table, a z-score of -2.57 cuts off 0.005 in the left tail; given the formula for z-score
(x-μ)/σ
we shall have:
(x-5000)/50=-2.57
solving for x we get:
x-5000=-128.5
x=-128.5+5000
x=4871.50