Easiest method solving 2 unknowns is Substitution.
So there will normally be 2(ormore)equations given.
Say
X+Y= a
bX=cY + d
a b c d are numbers they give
So first we rearrange the first equation
X = a - Y
No we substitute this into the 2nd equation so that we can get Y
since we know X = a-Y,
b(a-Y) = cY + d
we rearrange and we can find Y for this, it is just Y and numbers
hence finding Y, we sub the value for Y into X = a-Y and we get X also .

7 0

3 years ago

In the form of a paragraph, explain in complete sentences, your answers to the following questions. Include the final answer in

Yanka [14]

Lisa is an avid runner and is training for a marathon, so she runs everyday to achieve this purpose. In this way, she goes out to run for six days, so we have the following data set regarding the miles she runs:

1st day = 3.2 miles
2nd day = 7.5 miles
3rd day = 9.8 miles
4th day = 11.5 miles
5th day = 2.9 miles
6th day = 3.5 miles

Finally, she ran a total of:

3.2+7.5+9.8+11.5+2.9+3.5 = 38.4 miles

What was the average distance of each run?

This result can be get as the sum of each run (or the total of miles she run) divided by the numbers of days she ran.

 $A=\frac{38.4}{6}=6.4mi$

Lisa's goal for this week is to run an average of 6 miles per day. How many miles does she need to run tomorrow (the 7th day) in order to achieve her goal of 6 miles per day for the week?

Let's name x the distance she must run tomorrow. Therefore, the equation for this purpose is given as follows:

 $\frac{3.2+7.5+9.8+11.5+2.9+3.5+x}{7}=6$

∴ $\frac{38.4+x}{7}=6$

Isolating x:

$38.4+x=42$

∴ $x=42-38.4=3.6$

Therefore, she need to run:

$\boxed{3.6mi}$ in order to achieve the goal of 6 miles per day.

4 0

3 years ago