<h3>Given</h3>
P = 3r + 2s
<h3>Find</h3>
the corresponding equation for s
<h3>Solution</h3>
First of all, look at how this is evaluated in terms of what happens to a value for s.
- s is multiplied by 2
- 3r is added to that product
To solve for s, you undo these operations in reverse order. The "undo" for addition is adding the opposite. The "undo" for multiplication is division (or multiplication by the reciprocal).
... P = 3r + 2s . . . . . . starting equation
... P - 3r = 2s . . . . . . -3r is added to both sides to undo addition of 3r
... (P -3r)/2 = s . . . . . both sides are divided by 2 to undo the multiplication
Note that the division is of everything on both sides of the equation. That is why we need to add parentheses around the expression that was on the left—so the whole thing gets divided by 2.
Your solution is ...
... s = (P - 3r)/2
<h3>
Answer: f(x) = (-1/2)x+1, choice B</h3>
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Explanation:
The diagonal line passes through 1 on the vertical y axis. So the y intercept is b = 1. This means the location of the y intercept is (0,1).
Start at (0,1) and move down 1 and to the right 2 to arrive at (2,0). This is another point on the diagonal line. The motion of "down 1 and right 2" is effectively the slope
slope = rise/run = -1/2
rise = -1, run = 2
The rise being negative means we have gone downhill as we move to the right.
With m = -1/2 as the slope and b = 1 as the y intercept, we go from y = mx+b to y = (-1/2)x+1
The last thing to do is replace y with f(x) to get f(x) = (-1/2)x+1 as the final answer.
-4 is your answer hope this helps
