<span>2a(5-b)=3b+7
<em>[open bracket]</em>
10a - 2ab = 3b + 7
<em>[solve for b, so we need to move all terms with b to the left]</em>
<em>[-3b on both sides]</em>
10a - 2ab - 3b = 3b + 7 - 3b
10a - 2ab - 3b = 7
<em>[move all those without b to the right]</em>
<em>[-10a on both side]</em>
10a - 2ab- 3b - 10a = 7 - 10a
-2ab - 3b = 7 - 10a
<em>[divide by -1 through to change b to be positive]</em>
2ab + 3b = 10a - 7
<em>[take b out as the common factor]</em>
</span>b(2a + 3) = 10a - 7<span>
<em>[divide by (2a+3) through]</em>
b = (10a -7)/(2a+3)
</span>
<span>So we need to find the average speed of the bus that travels 20 km in 30 minutes. Average speed is defined as: Average speed=distance travelled/time taken or: v=s/t. We know s=20 km and t=30 minutes=0.5h. So after we input our numbers in the equation, we get: v=20km/0.5h=40km/h. So the correct answer is C) 40km/h.</span>
So to set up the equation we have:
<span><span><span>4M</span><span>4+M</span></span>=<span>127</span></span>
<span>28M=12(4+M)</span>
<span>28M=48+12M</span>
<span>28K−12M=48</span>
<span>(28−12)M=48</span>
<span>16K=48</span>
<span>M=<span>4816</span></span>
<span>M=3</span>
So Marna can clean the chimney alone in 3 hours
7.44-6.26=1.18
1.18 in minutes is 78 minutes bc 1 hour is 60 minutes + 18 minutes is 78
Hope this helps :D
Answer:
A $12.84
Step-by-step explanation:
Sweater was originally $48.00 before tax. $48.00 x 7% tax rate (.07) = $3.36 in tax
So the sweater originally would've cost $48.00 + $3.36 = $51.36
The sale price was 25% off the $48.00. $48.00 x 25% (.25) = $12.00
Then you subtract the $12.00 from the $48.00 to get the new price of $36.00
Now that's before tax, so $36.00 x 7% tax rate (.07) = $2.52 in tax
So the sweater would cost on sale $36.00 + $2.52 = $38.52
To figure out how much she would've saved you subtract the sale price & tax from the original price & tax $51.36 - $38.52 = $12.84
