I'll go over part A.
What's happening is that we are plugging some unknown number x into the function, and getting -1 as the result. The function rule is 3*x-7 which translates to "multiply the input number by 3, then subtract off 7"
Notice how multiplication comes first and then we subtract. This is following the order of operations PEMDAS (some books may call it BEDMAS depending on your region). The M for multiplication comes before the S for subtraction.
To isolate x, we follow the order of operations in reverse. We undo the "subtract off 7" then we undo the "multiply by 3"
So this is how it all works out
f(x) = 3x-7
-1 = 3x-7 .... replace f(x) with -1
3x-7 = -1
3x-7+7 = -1+7 ... add 7 to both sides to undo the "-7"
3x = 6
3x/3 = 6/3 ... divide both sides by 3 to undo the "multiplication"
x = 2
Therefore, if the input is 2, then output is -1
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Let's plug x = 2 into the function and see what happens
f(x) = 3x-7
f(2) = 3*2-7 .... replace x with 2
f(2) = 6-7 .... multiply
f(2) = -1 .... subtract
The input x = 2 leads to the output -1
So this confirms that x = 2 is the proper answer for part A
Answer:
3x2y−3xy+12x−12
Take out 3xy common from first two terms and 12 from last two terms.
3xy(x−1)+12(x−1)
(x−1)(3xy+12)
Given that there are 10 children who own a dog, and 14 children who do not, the ratio of the children that owns a dog to the children that do not own a dog, is 10:14.
To express the ratio in a simplify fraction, we will just use fractional notation. Thus, it is simply 10/14, or 5/7 as its simplest form.
Answer:
for 15 crayons box she can spend
Step-by-step explanation:
The computation of the number of crayons for which she can spend is shown below:
Given that
She can spend $30
And, the cost is 2 per box
So, for the number of crayons for which she can spend is
= $30 ÷ 2
= 15 crayons box
Hence, for 15 crayons box she can spend
The same would be relevant
D. Distributed Property of Multiplication over Addition. Happy Thanksgiving. Hope this helps.