4) 21
5) 36
6) 29.25
I used porpotions on all of these.
Sorry I don't remember the units.
Answer:
m = -2
b = 3.5 or (0, 3.5)
Step-by-step explanation:
y = mx + b
m = slope
b = y-intercept
y − 3.5 = −2x
y = -2x + 3.5
m = -2
b = 3.5
<span><span><span><span>2x</span>+<span>3y</span></span>=1</span>;<span><span>x+<span>4y</span></span>=<span>−2
</span></span></span>Steps:
<span>Multiply the second equation by -2, then add the equations together.
</span><span>(<span><span><span>2x</span>+<span>3y</span></span>=1</span>)
</span><span><span>−2</span><span>(<span><span>x+<span>4y</span></span>=<span>−2</span></span>)
</span></span>Becomes:
<span><span><span>2x</span>+<span>3y</span></span>=1
</span><span><span><span>−<span>2x</span></span>−<span>8y</span></span>=4
</span>Add these equations to eliminate x:
<span><span>−<span>5y</span></span>=5
</span>Then solve<span><span>−<span>5y</span></span>=5</span>for y:
<span><span><span>−<span>5y</span></span><span>−5</span></span>=<span>5<span>−5</span></span></span>(Divide both sides by -5)
<span>y=<span>−1
</span></span>Now that we've found y let's plug it back in to solve for x.
Write down an original equation:
<span><span><span>2x</span>+<span>3y</span></span>=1
</span>Substitute<span>−1</span>foryin<span><span><span><span>2x</span>+<span>3y</span></span>=1</span>:
</span><span><span><span>2x</span>+<span><span>(3)</span><span>(<span>−1</span>)</span></span></span>=1
</span><span><span><span>2x</span>−3</span>=1</span>(Simplify both sides of the equation)
<span><span><span><span>2x</span>−3</span>+3</span>=<span>1+3</span></span>(Add 3 to both sides)
<span><span>2x</span>=4
</span><span><span><span>2x</span>2</span>=<span>42</span></span>(Divide both sides by 2)
<span>x=2
</span>Answer:
<span><span>x=<span><span>2<span> and </span></span>y</span></span>=<span>−<span>1
</span></span></span>
Answer:
36
Step-by-step explanation:
hope this helps
8+7+5+7+9
15+5+7+9
20+7+9
27+9
36
Answer:
<h2> 2.32dollar/mile</h2>
Step-by-step explanation:
step one:
Given the function
y = 14 +2.31x + 4.50
we can solve for the rate of change by applying differentiation.
step two:
differentiating y which is cost with respect to x which is the miles
dy/dx= 0+2.32+0
dy/dx=2.32
Hence the rate of change of cost in the dollar to a mile is
2.32dollar/mile
