Answer:
y = -.5x -.5
Step-by-step explanation:
All you do is plug in the x and y in the point to the equation, y = mx + b. Since the coordinate is (5, -3), this in the equation would look like -3 = -.5(5) +b. (all you need to find is the y-intercept, or b.) Solve it out to get -3 = -2.5 + b. Add 2.5 to each side of the equation, you're left with b = -.5. Now, put that back into the original equation, and get y = -.5x -.5. I think this is right, you can go back through and check once more if you'd like.
LlL-=2-3=2=3-2=94308500496-405=4
Be sure to include the "=" sign: <span>f(x) = 2^x -7
To find the x-intercepts, set f(x) = 0 and solve for x: 2^x - 7 = 0,
or
2^x = 7
Take the common log of both sides: x log 2 = log 7
log 7
Solve for x: x = --------- = 2.81 (approx)
log 2
</span>
Answer:
<em>The second choice is correct. It can be factored as:</em>
Step-by-step explanation:
<u>The Difference of Squares Method for Factoring</u>
The expression:
Is a widely used method to factor binomials that are expressed as the subtraction of two perfect squares.
The condition for a binomial to be factored by using this method is that both terms must have an exact square root and they must be subtracted.
The last two choices are not valid because they are not a subtraction but an addition.
The first choice is not valid because none of the terms is a perfect square.
The second choice is correct. It can be factored as:
This problem can be solved by the chicken rabbits method or you can just do simple algebra.
I.) Chicken and rabbits method
First assume all 110 coins are dimes and none are quarters.
We will have a total value of 11 dollars
Now for each dime we switch out for a quarter, we adds 15 cents to the total value.
18.50-11=7.50 dollars
There are 750/15=50 group of 15 cents in the 7 dollars and 50 cents.
This also meant that we need to switch out 50 dimes for 50 quarters.
So we have 50 quarters.
That first method is very good and very quick once you get the hang of it, now I'm going to show you the algebraic way to solve this.
Let's say there are x dimes and y quarters.
Set up equation
x+y=110
10x+25y=1850
Now solve multiply first equation by 10
10x+10y=1100
subtract
15y=750
y=50
Now we set the numbers of quarters to y so the answer is 50 quarters.
I personally recommend using algebra whenever you can because the practice is very important and you will eventually get really fast at setting up and solving equations. The first method is faster in this case but the second is more generalize, hope it helps.
